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 2 · Income tax
What is the average income on tax returns in your ZIP code?
The interactive chart needs JavaScript. The numbers are on the chart's page.
Type any ZIP code to see the average income on the tax returns filed from it in tax year 2023, next to its state's and the U.S. average of $96,717. ZIP code 20001 in Washington, D.C., shown first, averaged $126,264. In tax year 2022, across the 27,588 ZIP codes in the data, half averaged less than about $68,300, and the highest was Fisher Island, Florida (33109), at $4.4 million on 400 returns. Income here is adjusted gross income, the income on a tax return after a few adjustments; an average can be pulled far up by a few very large incomes, and one return can cover a married couple. The IRS leaves out ZIP codes with fewer than 100 returns, single buildings and nonresidential ZIP codes, and returns with negative income. Tax year 2023 is the newest year the IRS has published by ZIP code.
Questions to discuss
- In one sentence of your own, what does this chart show?
- Find the biggest change or difference in the chart. What might explain it?
- Who collected these numbers, and how recent are they? What else would you want to know before drawing a conclusion?
Source: IRS Statistics of Income, individual income tax ZIP code data (Public domain (U.S. government work)) · Data as of Dec 31, 2023
Open the chart and its numbersChart 2 of 2 · 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
- How many cities on the chart have a murder rate above the U.S. rate, and how many are below it?
- Why does a chart like this use murders per 100,000 people instead of the total number of murders in each city?
- 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
Open the chart and its numbersTeachers: make your own chart assignment, or change this one. Free, no account needed.