more U.S. attorneys, less time spent in court

Hmmm. 

In 1989, the 2,632 U.S. attorneys spent 947,000 hours in court-related work.

In 2010, the 6,075 U.S. attorneys spent only 596,000 hours in court-related work.

I am not quite sure what to make of these numbers except to connect them to this:

Guilty pleas last year resolved 97% of all federal cases that the Justice Department prosecuted to a conclusion. That is up from 84% in 1990. During that period, the number of federal defendants nearly doubled amid a crackdown on crimes ranging from drug trafficking to fraud, while the number going to trial fell by nearly two-thirds.

When mandatory minimum sentencing lets prosecutors force the defendant to choose between the very, very long sentence probable if he goes to trial and the very long sentence offered in a plea agreement, few defendants go to trial. No trial, less court-related work.

Those numbers start to make sense except I don't know how to explain the huge increase in the number of U.S. attorneys. Unless the phrase "gravy train" helps.