Chart assignment

Charts to read and discuss

Read each chart, then answer its questions. Every chart shows its source and date; open it for a table of the numbers and the data to download.

  1. How fast has the world come online?
  2. How long do Americans live, and how has that changed since 1900?
  3. Which big U.S. cities have the highest murder rates?

Chart 1 of 3 · World

How fast has the world come online?

The interactive chart needs JavaScript. The numbers are on the chart's page.

73.6% of the world's people used the internet in 2025, up from 15.6% in 2005, the first year the World Bank gives a world figure. It counts people who used the internet at least once in the previous three months. The world figures are estimates by the International Telecommunication Union.

How to read this chart

Each point is the share of the world's people who used the internet at least once in the previous three months, as estimated by the International Telecommunication Union. The axis starts at zero, so the height shows the true share. The steeper the line, the faster people were coming online.

Questions to discuss

  1. About what share of the world was online in the first year on the chart, and in the latest year?
  2. Did the share grow faster in some years than others? What could have sped it up?
  3. Using the internet once in three months counts here. What does this number leave out about how people get online?

Chart 2 of 3 · Health

How long do Americans live, and how has that changed since 1900?

The interactive chart needs JavaScript. The numbers are on the chart's page.

A baby born in the US in 2018 could expect to live 78.7 years, up from 47.3 in 1900. The sharpest drop was in 1918, to 39.1 years, during the influenza pandemic. This CDC dataset stops at 2018; later NCHS reports put life expectancy at 78.4 years in 2023 and 79.0 in 2024, after a fall during the COVID-19 pandemic.

How to read this chart

Each point is how long a baby born in that year could expect to live, if death rates stayed as they were that year. It is an average, so it is pulled down a lot when many babies and young people die. Hover or tap a point to read its year and value.

Questions to discuss

  1. Find the sharpest drop on the chart. What happened in the world that year?
  2. Life expectancy in 1900 was under 50. Does that mean most adults died in their 40s? What else could lower the average?
  3. What changes in medicine, food or public health could explain the long rise?

Source: CDC National Center for Health Statistics, Death rates and life expectancy at birth (Public domain (U.S. government work)) · Data as of Dec 31, 2018

Open the chart and its numbers

Chart 3 of 3 · Crime

Which big U.S. cities have the highest murder rates?

The interactive chart needs JavaScript. The numbers are on the chart's page.

In 2025 St. Louis, MO had the highest murder rate of the 89 biggest U.S. cities whose police reported a full year to the FBI, about 51.3 per 100,000 people, followed by Memphis, TN (31.0) and Cleveland, OH (28.0). Irvine, CA (0.0) and Plano, TX (0.7) had the lowest; the U.S. rate was about 4.4. Departments that didn't report a full year are left out (for 2025, New Orleans, Orlando and St. Petersburg, Florida). Each rate is per person the department serves, and a few, such as Las Vegas, Honolulu, Jacksonville and Louisville, serve their whole county. A city's rate also depends on where its borders fall, so compare cities with care.

How to read this chart

Each bar is the number of murders in a city in one year for every 100,000 people its police department serves. The dashed line is the U.S. rate. Murders are rare, so in a smaller city a handful more or fewer in one year can move its rate and its rank a lot.

Questions to discuss

  1. How many cities on the chart have a murder rate above the U.S. rate, and how many are below it?
  2. Why does a chart like this use murders per 100,000 people instead of the total number of murders in each city?
  3. A city's rank can jump from one year to the next. Why might small numbers make rates bounce around?

Source: FBI Crime Data Explorer, Uniform Crime Reporting Program (Public domain (U.S. government work); source FBI Uniform Crime Reporting Program) · Data as of Dec 31, 2025

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