The FBI has released their Uniform Crime Report Crime in the United States numbers for year-end 2009 and, once again, the rate of crimes reported to police continues to fall.

I’ve just begun to explore the new report, but researchers can easily download spreadsheets to show long- and short-term trends in both population-adjusted rates and raw numbers. The chart above shows the crime decline since 1990 in murder, rape, robbery, aggravated assault, motor vehicle theft, burglary, and larceny-theft. This chart makes it apparent how much the overall crime numbers are driven by larceny-theft — and the comparative rarity of violent crimes such as rape and murder.

But crime is dropping across each of these categories. The purple bars show the magnitude of the drop in the past 20 years, comparing 1990 rates with 2009 rates, or ((2009-1990)/1990). The green bars show the most recent change from 2008 to 2009 ((2009-2008)/2008). I’d normally compare these numbers with those from the National Crime Victimization Survey before drawing any big conclusions about crime trends. With regard to the FBI’s official crime index, however, it seems pretty clear that there has been a significant drop in crime reported to police over the past year and, for that matter, over the past twenty years.