I find that this really varies from person to person. A few training examples of some people of I've run against:
Runner A: State runner up, D1 Big 10 Ten runner. 14:15 5K PR on the track, 80mpw, daily training paces are anywhere from 6:15-6:45 for every run.
Runner B: 30 years old, 16:35 5K PR on the roads, 4:45 mile PR, ran 1:59 800m last year!, runs 50mpw, does absolutely brutal track workouts, daily training paces are 7:00-7:25
Runner C: 22 years old, 18:05 5K on the roads, 3:05 marathoner, 35 mpw, daily training paces are 6:15-6:30. He is a moron.
Runner D: 28 years old, 17:07 5K PR, has competed in 50 to 100 mile trail racs, 100-120 mpw, daily training paces are 8:00-9:40.
As you can see, different strokes for different folks. A lot of it is what you are trying to achieve and train accordingly. I always use the Daniels vDot calculator:
http://www.runbayou.com/jackd.htm
and find that it's pretty accurate.