Estimated value of goods and services distributed for free on the Internet in 2011 : $376,000,000,000

Portion of the content streamed on Pornhub, the world’s largest pornography website, that is viewed on mobile devices : 1/2

Maximum number of dildos a Texan may legally own : 5

Chance that a pregnant U.S. woman says she is a virgin : 1 in 125

Age at which first cousins may marry, according to Utah law : 55

Number of U.S. states that make undisclosed exposure to HIV a criminal offense even in cases where a condom is used : 36

Number of states in which it is a felony for an HIV-positive person to spit on a police officer : 5

Percentage change in the global AIDS mortality rate since 2005 : –30

In the global cancer mortality rate : +8

Factor by which the annual number of deaths related to illegal drug use has increased worldwide in the past two decades : 2.3

Projected percentage increase in the legal market for marijuana in the United States this year : 63

Value of legal marijuana displaced to the black market by federal enforcement actions in the past three years : $250,000,000

Amount Americans spent on vitamins in 2012 : $9,200,000,000

Chance that a vitamin outperforms a placebo in a peer-reviewed study, according to a November 2013 analysis : 1 in 12

Percentage change in the past five years in the portion of Republicans who believe in evolution : –26

Portion of U.S. students who started college in 2007 who have not completed their degrees : 1/2

Percentage of students enrolled in a massive open online course who view no more than one lecture : 49

Percentage who complete the course : 4

Percentage of students enrolled in such courses at UPenn last year who had already earned a college degree : 79

Portion of the thirty professions projected to grow fastest over the next ten years that require postsecondary education : 2/3

Percentage change since 1980 in the rate of labor-force participation among U.S. women : +5.7

Among U.S. men : –7.7

Number of high school students in Mississippi who took the Advanced Placement test in computer science last year : 1

Portion of white U.S. students taking AP math exams last year who received passing scores : 2/3

Of black U.S. students : 1/3

Number of the 882 SAT takers from Camden, New Jersey, in 2012 who were scored “college-ready” : 3

Percentage of Syrian child refugees who are not attending school : 68

Amount Afghanistan spent on government programs last year : $5,300,000,000

Portion of that spending funded by government revenue : 2/5

Number of telephone lines on a terrorist “alert list” that were monitored daily by the NSA from 2006 to 2009 : 17,835

Percentage of those lines that met the agency’s legal standard for “reasonable articulable suspicion” of terrorism : 11

Percentage increase in the number of reported anti-Muslim hate crimes in the United Kingdom over the past year : 100

Factor by which the amount Britons owe in mortgage debt has increased since 1999 : 2.6

Portion of Americans who spend more than half their monthly income on rent : 1/4

Percentage change since last year in the amount of untaxed income Americans are allowed to spend on mass transit : –47

On parking : +2

Price of an Occupy Wall Street poster being sold by Walmart : $52.25

Number of Academy Award winners in the past twenty years who thanked God in their acceptance speeches : 7

Who thanked Harvey Weinstein : 30

Figures cited are the latest available as of January 2014.

“Harper’s Index” is a registered trademark.

March Index Sources

1 MIT Center for Digital Business (Cambridge, Mass.)

2 Pornhub (Luxembourg)

3 Legislative Reference Library of Texas (Austin)

4 Amy Herring, UNC Gillings School of Global Public Health (Chapel Hill, N.C.)

5 Utah Office of the Attorney General (Salt Lake City)

6,7 Yale Interdisciplinary Center for Bioethics (New Haven, Conn.)

8 World Health Organization (Washington)

9 International Agency for Cancer Research (Lyon, France)

10 World Health Organization (Geneva)

11,12 ArcView Market Research (San Francisco)

13 Euromonitor International (Chicago)

14 U.S. Preventive Services Task Force (Rockville, Md.)

15 Pew Research Center (Washington)

16 National Student Clearinghouse Research Center (Washington)

17,18 University of Pennsylvania Graduate School of Education (Philadelphia)

19 University of Pennsylvania (Philadelphia)

20–22 U.S. Bureau of Labor Statistics (Washington)

23–25 The College Board (N.Y.C.)

26 Camden City School District (Camden, N.J.)

27 United Nations High Commissioner for Refugees (Washington)

28,29 Afghan Ministry of Finance (Kabul)

30,31 Electronic Frontier Foundation (San Francisco)

32 Faith Matters (London)

33 Bank of England (London)

34 Joint Center for Housing Studies, Harvard University (Cambridge, Mass.)

35,36 Internal Revenue Service (Washington)

37 Walmart (Bentonville, Ark.)

38,39 Harper’s research