I rode for two summers from 1st grade to second grade and am on my third year of proffesional riding.. so about 3 1\2 years, I guess.
Highest I've jumped was 2'9, I was scared though and only jumped it about four times, shaking like a scared puppy. Haha..
After that, though, I jumped 2'6 and had a great time. =]
Now adays I'm working from 1'8 to 2'3.