Percentage of all litter on U.S. roadways accounted for by cigarette butts : 36

Estimated additional hours Americans would spend stoned annually if marijuana were legal in most states : 30,000,000,000

Ounces of marijuana left so far this year in “amnesty boxes” at the Colorado Springs airport : 1.4

Boxes of cookies a Girl Scout sold in two hours this February outside a San Francisco marijuana dispensary : 117

Percentage change since 2000 in the average cost of food worldwide : +123

Portion of U.S. minimum-wage earners who are older than twenty-five : 1/2

Number of inmates a Chicago county jail has successfully enrolled in Medicaid through provisions of Obamacare : 2,629

Percentage of all reported U.S. data breaches last year that occurred at health-care organizations : 43

Number of fraudulent background checks the firm that vetted Edward Snowden submitted to the U.S. government : 665,000

Email accounts a company specializing in spying on unfaithful partners hacked before being shut down by the FBI last year : 5,921

Percentage of same-sex marriages performed in Iowa that have been between people from out of state : 70

Years by which the life expectancy of an American with homophobic views is shorter than that of the average American : 2.5

By which the life expectancy of a gay person living in a homophobic community is : 12

Factor by which a Briton is more likely to die prematurely of loneliness than of obesity : 2

Portion of college students with symptoms of clinical depression who are not receiving mental-health services : 1/2

Percentage change in the Facebook activity of a newly single person on the day he or she is dumped : +225

Factor by which a person in the developing world is more likely to be diabetic if he or she has a television, computer, and car : 2.5

Estimated number of homeless people in Greece : 20,000

Of unoccupied homes there : 300,000

Amount of investment in Malta that will buy a foreigner E.U. citizenship, under a new Maltese law : $1,150,000

Number of mine-resistant trucks the Army plans to donate to domestic law enforcement and foreign governments : 12,400

Chances that a young Afghan man says he has never heard of 9/11 : 9 in 10

Percentage change in the number of active anti–federal government groups during President Obama’s first term in office : +800

Since his reelection : –20

Amount in royalties the band Skinny Puppy is seeking for the use of its music during U.S. military interrogations : $666,000

Estimated percentage of women in the U.S. military who are “very interested” in taking combat positions : 9

Portion of American Catholics who believe that the Church should ordain women : 2/3

Percentage of U.S. married men who say their spouses vote the same way they do : 73

Of U.S. married women who say so : 49

Portion of U.S. kindergartners who are the children of single mothers : 2/5

Chance an average American child eats pizza on any given day : 1 in 5

Amount Americans spent on mayonnaise last year : $2,000,000,000

Portion of North American zoo elephants that are overweight : 3/4

Percentage change since 2004 in the total membership of the World Clown Association : –30

Amount an Italian chocolatier spent to construct a 1.5-ton life-size chocolate sculpture of Pope Francis : $41,847

Percentage change in the past decade in the number of U.S. films and TV shows that featured an abortion-related plotline : +100

In the number of those plotlines that ended in an abortion : –14

Minimum percentage change in the past year in the number of reported cases of sexual assault in the U.S. military : +50

Date on which the Army suspended its chief sexual assault prosecutor for an alleged sexual assault : 2/21/2014

Figures cited are the latest available as of March 2014. 
“Harper’s Index” is a registered trademark.

May Index Sources

1 Keep America Beautiful (Stamford, Conn.)
2 Jonathan P. Caulkins (Pittsburgh)
3 Colorado Springs Police Department
4 Girl Scouts of Northern California (Alameda)
5 Food and Agriculture Organization of the United Nations (Rome)
6 Arindrajit Dube, University of Massachusetts Amherst
7 Cook County Sheriff’s Office (Chicago)
8 Identity Theft Resource Center (San Diego)
9 Beasley Allen Law Firm (Montgomery, Ala.)
10 Federal Bureau of Investigation (Los Angeles)
11 Iowa Department of Public Health (Des Moines)
12,13 Mark Hatzenbuehler, Columbia Mailman School of Public Health (N.Y.C.)
14 John Cacioppo, University of Chicago; Education Foundation (Atlanta)
15 Daniel Eisenberg, University of Michigan (Ann Arbor)
16 Facebook Data Science (Menlo Park, Calif.)
17 Scott Lear, Simon Fraser University (Vancouver)
18 Klimaka (Athens)
19 Hellenic Property Federation (Athens)
20 Permanent Mission of the Republic of Malta to the United Nations (N.Y.C.)
21 U.S. Department of Defense
22 International Council on Security and Development (Brussels)
23,24 Southern Poverty Law Center (Montgomery, Ala.)
25 Another ReyBee Production (Weehawken, N.J.)
26 U.S. Army Training and Doctrine Command (Fort Eustis, Va.)
27 Bendixen & Amandi International (Miami)
28–30 Lake Research Partners (Washington)
31 U.S. Department of Agriculture (Beltsville, Md.)
32 Euromonitor International (Chicago)
33 Cheryl Meehan, Elephant Welfare Study (Portland, Ore.)
34 World Clown Association (Merrillville, Ind.)
35 Mirco Della Vecchia (Belluno, Italy)
36,37 Gretchen Sisson, University of California, San Francisco
38 Sexual Assault Prevention and Response Office, U.S. Department of Defense
39 U.S. Army (Arlington, Va.)