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 are US prices rising?
  2. How fast has the world come online?
  3. How has the world's population grown since 1960?
  4. How much rarer is each step up in earthquake magnitude?

Chart 1 of 4 · Inflation

How fast are US prices rising?

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

The inflation rate was 3.7% in September 2026: how much consumer prices changed from the same month a year earlier. Each point makes that comparison, back to 1914, the first year BLS can compare. Inflation peaked at 23.7% in June 1920 and at 14.8% in March 1980; the 9.1% of June 2022 was the highest since 1981. Prices fell as fast as 15.8% a year in 1921 and 10.7% in 1932. BLS collected no prices in October 2025, during a lapse in federal funding, so that month and October 2026 are missing.

How to read this chart

Each point compares consumer prices in a month with the same month a year earlier. A value of 3 means things cost about 3% more than a year before; below zero means prices fell. The chart shows how fast prices change, not how high they are.

Questions to discuss

  1. Find two times when inflation was highest. What was happening in the country then?
  2. If inflation falls from 8% to 3%, are prices going down, or just rising more slowly?
  3. Find a stretch when the line is below zero. Why might falling prices be bad news for workers and businesses?

Source: U.S. Bureau of Labor Statistics, Consumer Price Index (CPI-U, all items) (Public domain (U.S. government work)) · Data as of Sep 30, 2026

Open the chart and its numbers

Chart 2 of 4 · 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 3 of 4 · World

How has the world's population grown since 1960?

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

The world had 8.22 billion people in 2025, about 2.7 times the 3.02 billion of 1960. It passed 8 billion in 2023. Figures are mid-year estimates from the United Nations, which revises them as new censuses come in.

How to read this chart

Each point is the number of people alive in the world in the middle of that year, estimated by the United Nations. The axis starts at zero, so the height of the line shows the true size. Look at how steep the line is to see how fast the population grew.

Questions to discuss

  1. Judging from the chart, about how many years did it take the world to add its most recent billion people?
  2. Is the line getting steeper or flatter in recent years? What does that tell you about the growth rate?
  3. These numbers are estimates that the UN revises. Why is it hard to count every person on Earth?

Source: World Bank, World Development Indicators: Population, total (CC BY 4.0 (credit the World Bank)) · Data as of Dec 31, 2025

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Chart 4 of 4 · Earthquakes

How much rarer is each step up in earthquake magnitude?

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

In 2025 the world recorded 6,428 earthquakes of magnitude 4.5 to 4.9, 1,983 of magnitude 5, 129 of magnitude 6, 15 of magnitude 7 and 1 of magnitude 8 or more. Each step up in magnitude is roughly ten times rarer, and releases about 32 times more energy. Countless smaller quakes go unrecorded worldwide, so the chart starts at 4.5.

How to read this chart

Each bar counts the earthquakes recorded worldwide in one year within a range of magnitudes. The bars start at zero. Each whole step up in magnitude releases about 32 times more energy, so a magnitude 7 quake is far more than one step stronger than a 6.

Questions to discuss

  1. Roughly how many times more common is each band than the one above it?
  2. The biggest bars are hard to compare with the smallest ones on this scale. What other way could you show these numbers?
  3. The chart starts at magnitude 4.5. Why might smaller earthquakes around the world go uncounted?

Source: U.S. Geological Survey, ANSS Comprehensive Earthquake Catalog (ComCat) (Public domain (U.S. government work); source U.S. Geological Survey) · Data as of Dec 31, 2025

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