Line chart with three lines: (1) total number of defendants in cases concluded in U.S. district courts' (2) number of defendants convicted; and (3) number of defendants imprisoned for the period 1980 through 2006.

The number of defendants prosecuted in U.S. district courts increased at an average annual rate of 4% between 1980 and 1993. Between 1993 and 1995, federal prosecutions decreased by 13%. Between 1995 and 2006, federal prosecutions increased at an average annual rate of 3%.

Convictions and imprisonments followed the same general pattern. As a proportion of convictions, imprisonments increased from 46% during 1980 to 80% during 2006.