I've seen 40+ in Reb and Passing, but not nearly as frequently.
I currently have a guy who's gone from 16-60 in LP and it's still blue. another guy 19 to 83 in PER (red now, couple points left).
Poking through some past rosters, once they started saving the ratings history, lots of 35ish pt gains in Ath, Spd, etc. LP and PER still the kings of High High growth though.