Even in some of the best general units 60% of your bucks are probably fawn or yearling bucks. This seems to be the case in the southern region units of Utah. I think 20-30% of the bucks are 2-3 year olds, and probably 10% or less are 4 year olds.The area I hunt has a history of great genetics, but even so, bucks that live beyond 5 years old are dang few. To get accurate data, you can't use the number of points a buck has to determine age. I saw a buck a couple weeks ago that was a 2x3 that had pipe mass, towering antlers, and the body the size of a steer. I think he was at least 5-6 years old.This is proof that even if a buck reaches 5-6 doesn't mean he will have a record set of antlers.A hunter needs to rely more on his own experience in the field, and less on scientific models.