Maybe someone in the 20 -29 group can speculate on the reasons for unexpectedly low numbers in that range. The only thing I can think of is that this group might be more seasonally intensive and are may use this site differently than a lot of us off-season users.
Although I've left this age group 20+ years ago, I'm guessing disposable income probably has a lot to do with this.
Yes, this is based on personal experience. I couldn't afford a sled until after I turned 30.