In 18.5 years flying (in a 20 year career) I accumulated about 5300 hrs, split between T-38, C-141 and T-39. What's that, about 300 hr/year, seems to be about the average for most over the long run.
I have a friend in the C-141 (now C-17) ANG unit I was working with, who flew 850 hr one year guard bumming, but you can't sustain that. Particularly after he got hired at FedEx.