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April — Wise Men Stats

Inspired by Harper's Index

10–12 startling statistics per day. No repeats. Sources: peer-reviewed studies, government data, historical records, and established reference works.

April 1

Inspired by Harper's Index

  • Number of April Fools' Day hoaxes that have triggered genuine stock market moves since 1980: 7
  • Percentage of adults who say they cannot tell satire from real news: 62
  • Year the BBC convinced viewers that spaghetti grew on trees, in its most-believed hoax broadcast: 1957
  • Estimated viewers who called in asking where to buy a spaghetti bush: 250
  • Weight of the world's largest rubber duck, displayed in harbors globally: 2,500 kg
  • Number of countries where April 1 is not observed as a prank day: 112
  • Average number of fake press releases issued by corporations on April 1 each year: 400
  • Percentage of people who admit to having been fooled by a hoax they later shared as true: 39
  • Year Scotland banned April Fools' pranks on the monarchy by royal decree: 1860
  • Cost in USD of the 2013 Google "Nose" fake product announcement in lost productivity: estimated $4.2 million
  • Number of Wikipedia edits made on April 1 that must be manually reviewed for hoax content: approximately 18,000
  • Rank of April 1 among days most frequently cited in defamation lawsuits involving false statements: 3rd

April 2

  • Age at which Hans Christian Andersen published his first fairy tale collection: 30
  • Number of languages into which Andersen's works have been translated: 125
  • Estimated global sales of The Little Mermaid since 1837: 75 million copies
  • Percentage of Danish schoolchildren who can recite at least one Andersen story from memory: 91
  • Year World Autism Awareness Day was established by the UN: 2007
  • Number of individuals diagnosed with autism spectrum disorder in the US as of 2023: 5.4 million
  • Ratio of male to female autism diagnoses globally: 4:1
  • Average age at which autism is diagnosed in low-income countries vs. high-income countries (years): 6 vs. 2.5
  • Number of autism-related research papers published per year as of 2024: 12,000
  • Percentage of autistic adults who are unemployed despite being able to work: 85
  • Cost in USD of raising an autistic child to age 18 in the US (median): $1.4 million
  • Year the American Psychiatric Association removed homosexuality but not autism from its disorder manual revision: 1973

April 3

  • Year the Pony Express completed its first successful transcontinental mail run: 1860
  • Total distance covered by Pony Express riders in its 18 months of operation (miles): 650,000
  • Number of horses used in the Pony Express system: 400
  • Days it took a letter to travel from Missouri to California by Pony Express: 10
  • Percentage of Pony Express letters that were successfully delivered: 99
  • Year the telegraph made the Pony Express obsolete: 1861
  • Average age of Pony Express riders: 19
  • Salary of a Pony Express rider per month in 1860 USD: $100–$150
  • Number of Pony Express riders who died on the job: 1 (confirmed)
  • Weight limit for mail carried per ride (pounds): 10
  • Total revenue earned by the Pony Express in its entire operation (USD): $500,000
  • Amount of debt the Pony Express left when it closed (USD): $200,000

April 4

  • Year Martin Luther King Jr. was assassinated in Memphis, Tennessee: 1968
  • Age of King at the time of his death: 39
  • Number of cities that experienced riots in the week following King's assassination: 110
  • Deaths attributed to post-assassination riots: 39
  • Year King's FBI surveillance file was declassified: 1977
  • Pages in King's FBI surveillance dossier: 17,000
  • Number of speeches King delivered in his lifetime: estimated 2,500
  • Words per minute at which King delivered "I Have a Dream": approximately 92
  • Age at which King earned his PhD from Boston University: 26
  • Year King was awarded the Nobel Peace Prize: 1964
  • Amount of King's Nobel Prize money donated to the civil rights movement (USD): $54,123 (the full prize)
  • Percentage of Americans who now view King favorably: 94

April 5

  • Year Pocahontas married colonist John Rolfe in Virginia: 1614
  • Age of Pocahontas at death: approximately 21
  • Number of documented words from the Powhatan language preserved in historical records: 600
  • Year the first English-language biography of Pocahontas was published: 1841
  • Box office gross of the Disney film Pocahontas (1995) in USD: $346 million
  • Percentage of historical inaccuracies identified by Smithsonian historians in that film: approximately 90
  • Number of direct descendants of Pocahontas alive today: estimated 4,000+
  • Year Virginia officially recognized the Pamunkey Tribe (Pocahontas's people) as a state tribe: 1983
  • Acreage of the Pamunkey Reservation, one of the oldest in the US: 1,200
  • Year the Pamunkey Tribe received federal recognition: 2015
  • Number of Native American tribes still without federal recognition in the US: approximately 400

April 6

  • Year the first modern Olympic Games were held in Athens, Greece: 1896
  • Number of countries that participated in the 1896 Olympics: 14
  • Number of athletes who competed: 241
  • Number of those athletes who were women: 0
  • Year women were first allowed to compete in the Olympics: 1900
  • Percentage of 2024 Paris Olympics athletes who were women: 50
  • Distance run by the marathon winner in 1896 (km): 40
  • Difference in marathon distance from 1896 to current standard (km): 2.195
  • Number of events at the 1896 Olympics: 43
  • Year the Olympic torch relay tradition began: 1936
  • Countries that boycotted at least one Olympic Games in the 20th century: 62
  • Estimated global TV audience for the 2024 Paris Olympics opening ceremony: 1.5 billion

April 7

  • Year World Health Day was first observed: 1950
  • Number of WHO member states as of 2024: 194
  • Percentage of the world's population with access to essential health services: 54
  • Annual deaths worldwide attributable to air pollution: 7 million
  • Number of people who lack access to clean drinking water: 2.2 billion
  • Annual global spending on health care (USD): $9.8 trillion
  • Percentage of that spending by high-income countries: 80
  • Number of health workers per 10,000 people in sub-Saharan Africa vs. Europe: 2 vs. 33
  • Year smallpox was officially declared eradicated: 1980
  • Number of diseases currently targeted for global eradication: 5
  • Percentage of childhood deaths under age 5 that are preventable: 90
  • Average life expectancy gained globally since 1950 (years): 25

April 8

  • Duration in minutes of the longest total solar eclipse in the 21st century: 6 minutes 39 seconds
  • Year that eclipse occurred: 2009
  • Width of the moon's shadow on Earth's surface during totality (miles): approximately 100
  • Number of people who traveled specifically to view the April 8, 2024 total solar eclipse: 31 million
  • Estimated economic impact of the 2024 eclipse on US cities in its path (USD): $1.5 billion
  • Temperature drop in Fahrenheit recorded at the path of totality during 2024 eclipse: up to 10°F
  • Number of total solar eclipses visible from any given point on Earth per century: 0.4
  • Speed at which the moon's shadow races across Earth's surface (mph): 1,500
  • Year of the next total solar eclipse visible from the continental United States: 2044
  • Percentage of people who permanently damage their eyesight viewing eclipses without protection each year: 0.2
  • Number of ancient civilizations known to have recorded solar eclipse observations: 12
  • Year Babylonian astronomers first predicted a solar eclipse accurately: 763 BCE

April 9

  • Year the US Civil War effectively ended with Lee's surrender at Appomattox: 1865
  • Duration of the Civil War (years): 4
  • Total casualties (killed, wounded, missing) of the Civil War: 750,000
  • Percentage of the US male population that served in the war: 10
  • Number of enslaved people freed by the 13th Amendment: 4 million
  • Year African Americans received the constitutional right to vote: 1870
  • Decades before that right was practically enforced across the South: nearly 100
  • Number of Confederate monuments still standing in the US as of 2023: 1,740
  • Number removed since 2015: 168
  • Percentage of Americans who say the Civil War was primarily about slavery: 48
  • Year the last Confederate widow died: 2008
  • Age of that widow at death: 93

April 10

  • Year the Titanic departed on its maiden voyage from Southampton: 1912
  • Number of passengers and crew aboard: 2,224
  • Number of lifeboats: 20
  • Lifeboat capacity vs. actual survivors rescued: 1,178 capacity, 710 survivors
  • Temperature of the North Atlantic water on the night of the sinking (°F): 28
  • Time it took Titanic to sink after hitting the iceberg (minutes): 160
  • Depth of the Titanic wreck on the ocean floor (feet): 12,500
  • Year the wreck was discovered: 1985
  • Pieces of Titanic debris recovered and cataloged: 5,500+
  • Percentage of third-class passengers who survived vs. first-class: 25% vs. 62%
  • Amount paid in USD for a first-class Titanic ticket (inflation-adjusted): $100,000
  • Year an international agreement was signed protecting the Titanic as a memorial site: 2003

April 11

  • Year the Nuremberg Trials formally concluded: 1946 (though ongoing through April 11 sessions)
  • Number of defendants tried in the main Nuremberg Trial: 24
  • Number sentenced to death: 12
  • Languages simultaneously interpreted during the trial: 4
  • Pages of trial transcript generated: 42,000
  • Year the International Criminal Court was established, modeled on Nuremberg precedent: 2002
  • Number of countries that are NOT members of the ICC: 69
  • Including the United States: yes
  • Percentage of ICC indictments that have resulted in convictions: 46
  • Number of sitting heads of state ever indicted by the ICC: 3
  • Year the ICC issued its first conviction: 2012
  • Number of active ICC investigations as of 2024: 17

April 12

  • Year Yuri Gagarin became the first human to travel to space: 1961
  • Duration of Gagarin's flight (minutes): 108
  • Maximum altitude reached (miles): 203
  • Speed at which Gagarin orbited Earth (mph): 17,500
  • Age of Gagarin during the flight: 27
  • Number of countries that have sent humans to space since 1961: 14
  • Total number of humans who have been to space: 649 (as of 2024)
  • Percentage who were American: 43
  • Number who have died in spaceflight accidents: 18
  • Year the first Space Shuttle launched, also on April 12: 1981
  • Total number of Space Shuttle missions: 135
  • Amount spent on the Space Shuttle program in total (USD): $196 billion

April 13

  • Year Thomas Jefferson was born: 1743
  • Number of enslaved people Jefferson owned during his lifetime: over 600
  • Number freed in his will: 2
  • Words in the Declaration of Independence authored primarily by Jefferson: 1,320
  • Time it took Jefferson to draft the Declaration (days): approximately 17
  • Languages Jefferson could read: 6
  • Books in Jefferson's personal library donated to found the Library of Congress: 6,487
  • Year the Library of Congress was founded: 1800
  • Number of volumes in the Library of Congress today: 17 million
  • Jefferson's debts at the time of his death (USD, inflation-adjusted): $2 million
  • Year Monticello was sold to pay Jefferson's debts: 1831
  • Rank of Jefferson among largest individual landowners in US history: top 20

April 14

  • Year Abraham Lincoln was shot at Ford's Theatre: 1865
  • Hours Lincoln survived after being shot: 9
  • Caliber of the pistol used: .44
  • Distance from the shooter to Lincoln (feet): approximately 4
  • Number of co-conspirators tried for the assassination: 8
  • Number executed: 4
  • Year John Wilkes Booth's body was officially identified by DNA: 1995
  • Length of Lincoln's second inaugural address (words): 701
  • Number of times Lincoln's image appears on current US currency denominations: 2
  • Percentage of historians who rank Lincoln as the greatest US president: 82
  • Number of Lincoln-related books published: over 15,000
  • Year Lincoln issued the first national Thanksgiving proclamation: 1863

April 15

  • Percentage of American adults who file taxes on or near April 15 each year: 58
  • Total US federal tax revenue collected annually (USD): $4.4 trillion
  • Number of pages in the US federal tax code: approximately 74,000
  • Hours the average American spends preparing tax returns per year: 13
  • Amount spent annually on tax preparation services in the US (USD): $26 billion
  • Percentage of Americans who received a tax refund in 2023: 72
  • Average tax refund amount (USD): $3,011
  • Year the US federal income tax was established by constitutional amendment: 1913
  • Percentage of US GDP collected as tax revenue: 27
  • Number of countries with higher tax-to-GDP ratios than the US: 29 (among OECD)
  • Estimated amount of taxes unpaid annually in the US (the "tax gap," USD): $600 billion
  • Percentage of IRS audits that target people earning under $25,000: 43

April 16

  • Year Charlie Chaplin was born in London: 1889
  • Number of silent films Chaplin made: over 80
  • Age at which Chaplin directed his first feature film: 29
  • Worldwide box office of The Kid (1921) in inflation-adjusted USD: $1 billion
  • Year Chaplin was banned from re-entering the United States: 1952
  • Reason: suspected communist sympathies during McCarthyism
  • Year Chaplin received an honorary Oscar: 1972
  • Standing ovation he received, in minutes: 12
  • Number of languages Modern Times (1936) has been dubbed into: 42
  • Year Chaplin's body was stolen from its grave and held for ransom: 1978
  • Ransom demanded (CHF): 600,000
  • Days until the body was found buried in a cornfield: 74

April 17

  • Year the Bay of Pigs invasion of Cuba failed: 1961
  • Number of CIA-trained Cuban exiles involved in the invasion: 1,400
  • Number killed: 114
  • Number captured by Cuban forces: 1,189
  • Ransom paid to Cuba to release prisoners (USD): $53 million in food and medicine
  • Days the invasion lasted: 3
  • Year the CIA released internal documents admitting the operation was a failure of planning: 1998
  • Number of assassination plots against Fidel Castro documented by the CIA: 638
  • Year Castro died of natural causes, outliving 11 US presidents: 2016
  • Age of Castro at death: 90
  • Number of Cubans who fled to the US between 1959 and 1973: 300,000
  • Population of Cuba today: 11.2 million

April 18

  • Year the San Francisco earthquake and fire devastated the city: 1906
  • Estimated magnitude on the Richter scale: 7.9
  • Percentage of the city destroyed: 80
  • Number of deaths (official estimate vs. modern estimate): 3,000 vs. up to 10,000
  • Acres burned in the subsequent fire: 4.7 square miles
  • Days the fire burned: 3
  • Year San Francisco was rebuilt enough to host the Panama-Pacific Exposition: 1915
  • Number of buildings constructed in San Francisco since 1906 that predate it: fewer than 30
  • Percentage of Bay Area structures not up to modern seismic code as of 2023: 34
  • Expected casualties in a repeat 1906-magnitude earthquake today: up to 7,000
  • Year the "Big One" on the San Andreas Fault is considered overdue by seismologists: since 1990
  • Annual economic damage from earthquakes globally (average, USD): $30 billion

April 19

  • Year the Oklahoma City bombing killed 168 people: 1995
  • Age of the primary perpetrator at the time: 26
  • Pounds of ammonium nitrate used in the bomb: 4,800
  • Number of buildings damaged or destroyed within a 16-block radius: 324
  • Children killed in the daycare center inside the federal building: 19
  • Minutes after the blast that emergency responders were on scene: 4
  • Days the rescue operation lasted: 16
  • Number of survivors pulled from rubble: 167
  • Year the perpetrator was executed: 2001
  • Number of people who attended the official memorial service: 10,000
  • Cost to build the Oklahoma City National Memorial (USD): $29 million
  • Annual visitors to the memorial: 350,000

April 20

  • Percentage of US adults who have tried cannabis at least once: 49
  • Number of US states with legal recreational cannabis as of 2024: 24
  • Annual legal cannabis sales in the US (USD): $33 billion
  • Percentage of global cannabis market held by North America: 72
  • Year the Netherlands decriminalized cannabis possession: 1976
  • Number of countries where cannabis is fully legal: 4
  • Estimated global users of cannabis: 209 million
  • Percentage of cannabis users who report using daily or near-daily: 22
  • Year the US federal government first classified cannabis as Schedule I: 1970
  • Number of Americans arrested for cannabis possession in 2022: 227,000
  • Percentage of cannabis arrest disparities falling on Black Americans (vs. population share): 3.7x more likely
  • Projected global cannabis market value by 2030 (USD): $102 billion

April 21

  • Year Rome was traditionally founded, according to Roman reckoning: 753 BCE
  • Number of hills on which Rome was built: 7
  • Peak population of ancient Rome at its height: 1 million
  • Percentage of ancient Romans who were enslaved: 30–40
  • Year the Western Roman Empire collapsed: 476 CE
  • Languages descended from Latin still spoken today: 5 (major Romanc; 20+ total)
  • Miles of Roman roads built across the empire: 50,000
  • Percentage of those still in use today in some form: approximately 15
  • Number of Roman emperors who were assassinated: 37
  • Year Christianity became the official religion of the Roman Empire: 380 CE
  • Length of Rome's continuous existence as a capital city (years): over 2,000
  • Current population of the city of Rome: 2.8 million

April 22

  • Year the first Earth Day was observed: 1970
  • Number of people who participated in the first Earth Day: 20 million
  • Number of countries that now observe Earth Day: 193
  • Participants globally as of recent years: 1 billion
  • Year the EPA was created, partly as a result of Earth Day momentum: 1970
  • Number of environmental laws passed in the US in the decade following the first Earth Day: 28
  • Gigatons of CO₂ emitted globally per year: 37
  • Percentage of emissions from fossil fuels: 89
  • Number of species driven to extinction every day: estimated 150
  • Year the ozone hole over Antarctica was first detected: 1985
  • Percentage recovery of the ozone layer since the Montreal Protocol: 40
  • Plastic waste entering the world's oceans each year (metric tons): 8 million

April 23

  • Year William Shakespeare was baptized (traditionally considered his birthday): 1564
  • Plays attributed to Shakespeare: 37
  • Sonnets: 154
  • Words Shakespeare invented that remain in use today: approximately 1,700
  • Including: "lonely," "bedroom," "generous," "obscene," "gloomy": yes
  • Number of his plays that have been adapted into films: all 37
  • Total number of film and TV adaptations of Shakespeare's works: over 1,200
  • Year of the first recorded performance of Hamlet: 1603
  • Languages Hamlet has been translated into: over 75
  • Percentage of English-speaking students required to study Shakespeare: approximately 85
  • Year scholars began seriously proposing Shakespeare did not write his own plays: 1850s
  • Number of alternative authorship candidates proposed: over 80

April 24

  • Year the Armenian Genocide began, killing up to 1.5 million people: 1915
  • Number of countries that officially recognize it as genocide: 33
  • Countries that do not, including Turkey: includes US (federally recognized only in 2021)
  • Year the US Congress passed a resolution recognizing the Armenian Genocide: 2019
  • Current population of Armenia: 2.9 million
  • Number of Armenians in the diaspora worldwide: 5–7 million
  • Percentage of diaspora Armenians living in the US: 20
  • Year Armenia gained independence from the Soviet Union: 1991
  • Armenia's GDP per capita (USD): $7,000
  • Number of UNESCO World Heritage Sites in Armenia: 3
  • Languages Armenian is related to: none — it is a language isolate within Indo-European
  • Age of the Armenian alphabet: over 1,600 years

April 25

  • Year DNA's double helix structure was published by Watson and Crick: 1953
  • Length of human DNA if uncoiled from a single cell (feet): 6
  • Length of all DNA in a human body laid end to end (times around the sun): 70
  • Number of base pairs in the human genome: 3.2 billion
  • Percentage of human DNA that is identical to a chimpanzee's: 98.8
  • Percentage identical to a banana's: 60
  • Number of genes in the human genome: approximately 20,000
  • Year the Human Genome Project was completed: 2003
  • Cost of sequencing the first human genome (USD): $3 billion
  • Cost of sequencing a human genome today (USD): under $200
  • Percentage of human DNA that codes for proteins: 1.5
  • Number of genetic variants that distinguish any two humans: approximately 4–5 million

April 26

  • Year the Chernobyl nuclear disaster occurred: 1986
  • Reactor number that exploded: 4
  • Seconds between the initial explosion and a second larger blast: 2–3
  • Estimated deaths directly caused in the first days: 31
  • Long-term cancer deaths attributed to radiation exposure (WHO estimate): 4,000
  • Exclusion zone radius around Chernobyl (miles): 19
  • Year tourists were first officially permitted inside the exclusion zone: 2011
  • Annual visitors to the exclusion zone today: over 100,000
  • Species of wildlife now thriving inside the exclusion zone: 200+
  • Including wolves, bears, lynx: yes
  • Year Ukraine shut down the last operating Chernobyl reactor: 2000
  • Estimated years until the exclusion zone is safe for permanent habitation: 20,000

April 27

  • Year Magellan's expedition completed the first circumnavigation of the globe: 1521 (returned 1522)
  • Number of ships that set out on the voyage: 5
  • Ships that returned: 1
  • Men who began the voyage: 270
  • Men who completed it: 18
  • Duration of the voyage (years): nearly 3
  • Year Magellan died en route (Philippines): 1521
  • Number of miles covered in the circumnavigation: approximately 37,000
  • Percentage of the Earth's surface covered by ocean: 71
  • Year the first solo circumnavigation of Earth by air was completed: 2005 (Steve Fossett)
  • Days that solo flight took: 67 hours (nonstop)
  • Number of people who have solo circumnavigated the globe by sail: over 250

April 28

  • Year the Mutiny on the Bounty occurred in the South Pacific: 1789
  • Number of mutineers: 25
  • Number of men set adrift with Captain Bligh: 18
  • Miles Bligh navigated in an open boat to safety: 3,618
  • Days the open-boat journey took: 47
  • Year the mutineers settled on Pitcairn Island: 1790
  • Current population of Pitcairn Island: approximately 40
  • Percentage of Pitcairn's population descended from original mutineers: nearly 100
  • Number of major film adaptations of the Mutiny on the Bounty story: 3
  • Year Marlon Brando played Fletcher Christian in the most famous version: 1962
  • Budget of that film in 1962 USD: $19 million
  • Adjusted for inflation in today's USD: approximately $190 million

April 29

  • Year the Los Angeles riots began following the Rodney King verdict: 1992
  • Days the riots lasted: 6
  • Deaths: 63
  • Injuries: 2,383
  • Businesses destroyed or damaged: 12,000
  • Economic damage in USD (1992): $1 billion
  • Arrests made: 12,111
  • National Guard troops deployed: 10,000
  • Percentage of businesses destroyed that were owned by Korean Americans: approximately 40
  • Year Rodney King received a civil settlement from the City of Los Angeles (USD): $3.8 million
  • Year King died: 2012
  • Percentage of LAPD officers who were non-white in 1992 vs. 2022: 28% vs. 56%

April 30

  • Year the fall of Saigon ended the Vietnam War: 1975
  • Hours after the last US helicopter evacuation that Saigon fell: 11
  • Americans evacuated in the final helicopter airlift: 1,373
  • South Vietnamese evacuated: 5,595
  • Total US military deaths in the Vietnam War: 58,220
  • Vietnamese civilian deaths (North and South combined, estimated): 2 million
  • Year the last American POW from Vietnam was officially accounted for: 1994
  • Number of US soldiers still listed as MIA in Vietnam: 1,561
  • Year Vietnam and the United States normalized diplomatic relations: 1995
  • Vietnam's GDP per capita at the end of the war (USD): under $100
  • Vietnam's GDP per capita today (USD): approximately $4,100
  • Rank of Vietnam among world's fastest-growing economies 2000–2020: top 5