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 is car insurance getting more expensive?
  2. How much rarer is each step up in earthquake magnitude?
  3. Which big U.S. cities have the most violent crime?

Chart 1 of 3 · Inflation

How fast is car insurance getting more expensive?

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

Car insurance prices changed by -5% in the 12 months to September 2026 (a minus sign means they fell). Their fastest rise since 1976 came in April 2024, when prices were 22.6% higher than in April 2023. Each point compares a month with the same month a year earlier. BLS priced car insurance only every few months before 1970, so the chart starts in 1971. BLS collected no prices in October 2025 and published none for car insurance in November 2025, so those months and the same months of 2026 are missing.

Questions to discuss

  1. In one sentence of your own, what does this chart show?
  2. Find the biggest change or difference in the chart. What might explain it?
  3. Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?

Source: U.S. Bureau of Labor Statistics, Consumer Price Index (motor vehicle insurance) (Public domain (U.S. government work)) · Data as of Sep 30, 2026

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Chart 2 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

  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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Chart 3 of 3 · Crime

Which big U.S. cities have the most violent crime?

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

In 2025, Memphis, TN had the highest violent crime rate of the 89 biggest U.S. cities whose police reported a full year to the FBI, about 1,853 per 100,000 people, followed by Detroit, MI (1,654) and Oakland, CA (1,475). Irvine, CA (79) and Virginia Beach, VA (101) had the lowest; the U.S. rate was about 330. Violent crime is murder, rape, robbery and aggravated assault. In 2025 the police in New Orleans, Orlando and St. Petersburg, Florida, didn't report a full year of crimes, so they are left out. 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 one big city's violent crimes reported to the FBI in a year (murder, rape, robbery and aggravated assault) for every 100,000 people its police department serves. The dashed line is the rate for the whole U.S. Dividing by population makes big and small cities fair to compare, but a city's rate also depends on where its borders fall.

Questions to discuss

  1. Find the city with the highest rate and the one with the lowest. About how many times higher is the top rate?
  2. Some departments police a whole county, suburbs included. How could that change a city's rate compared with one that covers only its downtown?
  3. These are crimes reported to police. What kinds of crime might never show up in these numbers, and why?

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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