Percentage change since 2009 in the number of Americans who play football : –17

Who play rugby : +77

Factor by which female college soccer players are more likely than male players to suffer concussions : 2

Portion of part-time faculty at U.S. colleges whose households receive government assistance : 1/4

Percentage of Americans aged 18 to 31 with credit-card and student-loan debt, respectively, in 1989 : 43, 18

Today : 36, 40

Percentage change since 1992 in the portion of jobs in the United States that require no high-school diploma : +1

That require a high-school diploma but no further degree : –12

Portion of high-school dropouts who say they left school to work : 1/4

Portion of those dropouts who earn less than $10,000 per year : 3/5

Percentage of applicants admitted last year to Stanford’s business school, the most selective in the country : 7

To the Indian Institute of Management, Ahmedabad : 0.24

Estimated number of new movie screens that open in China each day : 15

Minimum number of people displaced since 2004 by World Bank projects : 3,350,449

Portion of Syrians seeking asylum since 2011 who have been hosted by Turkey : 2/5

By the United States : 1/7,700

Percentage change since 2000 in the number of black African immigrants living in the United States : +137

Number of U.S. police officers who have been prosecuted in the past decade for shooting someone in the back : 28

Number convicted : 6

Ratio of unincarcerated men to unincarcerated women aged 25 to 54 among white Americans : 1:1

Among black Americans : 0.8:1

Among black residents of Ferguson, Missouri : 0.6:1

Number of the ten most challenged books at U.S. libraries last year whose main characters are non-white or LGBT : 8

Percentage of inmates in California men’s prisons who report being sexually assaulted while incarcerated : 4

Of transgender inmates in such prisons who do : 59

Percentage of water consumed annually by California’s agriculture industry that is used to grow alfalfa to feed livestock : 15

Minimum percentage of human breast milk sold online that contains cow’s milk : 10

Percentage change since 1975 in the portion of U.S. mothers who work outside the home : +51

In the number of hours the average married U.S. mother spends engaged in active child care each week : +88

Minimum percentage change since 2008 in the number of adult Americans prescribed medication for ADHD : +53

Number of previously unknown fly species discovered in Los Angeles in the past year : 30

Average age at which streaming-music listeners have their midlife crisis, according to Spotify : 42

Portion of Americans in 1984 who believed that “most people can be trusted” : 1/2

In 2014 : 1/3

Percentage of Americans with strong party loyalties who say that winning elections is more important than policy change : 41

Amount by which annual lobbying expenditures by U.S. corporations exceed the Congressional budget : $600,000,000

Amount the Secret Service has requested from Congress to build a replica of the White House : $8,000,000

Minimum number of months that George H. W. Bush’s home alarm was broken before the Secret Service fixed it last year : 13

Factor by which the mortality rate among hospital patients on television exceeds the actual rate : 9

Figures cited are the latest available as of May 2015.

“Harper’s Index” is a registered trademark.

July Index Sources

1,2 Sports & Fitness Industry Association (Silver Spring, Md.)
3 Datalys Center (Indianapolis)
4 Ian Perry, University of California, Berkeley
5,6 U.S. Federal Reserve Board of Governors
7,8 Center on Education and the Workforce, Georgetown University (Washington)
9,10 Urban Institute (Washington)
11 Stanford Graduate School of Business (Calif.)
12 Indian Institute of Management, Ahmedabad
13 Motion Picture Association of America (Washington)
14 International Consortium of Investigative Journalists (Washington)
15,16 Office of the United Nations High Commissioner for Refugees (Geneva)
17 Pew Research Center (Washington)
18,19 Philip M. Stinson, Bowling Green State University (Ohio)
20–22 Justin Wolfers, The Peterson Institute for International Economics (Washington)
23 American Library Association (Chicago)
24,25 Valerie Jenness, University of California, Irvine
26 California Department of Water Resources (Sacramento)
27 The Research Institute at Nationwide Children’s Hospital (Columbus, Ohio)
28 U.S. Bureau of Labor Statistics
29 Melissa Milkie, University of Toronto
30 Express Scripts (St. Louis)
31 Brian V. Brown, Natural History Museum of Los Angeles County (Los Angeles)
32 Spotify (San Francisco)
33,34 Tom W. Smith, NORC at the University of Chicago
35 Patrick R. Miller, University of Kansas (Lawrence)
36 Lee Drutman, New America Foundation (Washington)
37 Office of the Inspector General, U.S. Department of Homeland Security
38 U.S. Secret Service
39 Amir Hetsroni, Xi’an Jiaotong-Liverpool University (Karmei Yosef, Israel)