I'm in the 41-50 range - only 6.53% of people my age here with acne. And mine, though mostly under control using the regimen, shows no sign of going away after 17 years.
Without wishing to trivialize anyone else's problem, the teens and early 20s people here really shouldn't worry too much, especially those who acne isn't severe. People expect youngsters to have spots. When I was at school I was considered something of a freak for never getting them lol I've made up for it since.
I just turned 28 on August 1. From ages 13 - 22 I had acne and normally I could use either Avon, Mary Kay Loreal or Neutrogena and it would clear right up. I could bounce from product to product and I would be fine. I think now combined with my age since I am in the late 20s range, environment factors [too much sun makes me sensitive] that my acne is getting worse and worse. I am on a prescriotion acne cream [Tretinon A; Retin - A] provided by the dermatologist. It seemed fine at first and irritated me a little but nowadays I just seem to have all of these breakouts and pimples popping up.