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.
Chart 1 of 3 · 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
- Roughly how many times more common is each band than the one above it?
- The biggest bars are hard to compare with the smallest ones on this scale. What other way could you show these numbers?
- 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
Open the chart and its numbersChart 2 of 3 · Road safety
Are U.S. roads getting safer per mile driven?
The interactive chart needs JavaScript. The numbers are on the chart's page.
In 2024 there were 1.19 deaths for every 100 million miles driven, down from 3.35 in 1980. The lowest rate was 1.08 in 2014; it jumped to 1.34 in 2020, when people drove less but deaths rose. Miles driven are the Federal Highway Administration's estimates.
How to read this chart
Each point is the number of people killed in traffic crashes for every 100 million miles Americans drove that year. Dividing by miles driven turns a count into a rate, so years when people drove more or less can be compared fairly.
Questions to discuss
- About what fraction of the 1980 rate is the rate in the latest year?
- In 2020 people drove less, but the rate went up. What could explain that?
- Why is deaths per mile a fairer way to compare years than the total number of deaths?
Source: NHTSA Fatality Analysis Reporting System (FARS) and FHWA Highway Statistics (table VM-2) (Public domain (U.S. government work)) · Data as of Dec 31, 2024
Open the chart and its numbersChart 3 of 3 · 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
- Find two times when inflation was highest. What was happening in the country then?
- If inflation falls from 8% to 3%, are prices going down, or just rising more slowly?
- 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
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