Hey Trikerchicks, Welcome to TrikeTalk.
I don't think I've seen any specific statistics on here such as you have asked about. I do know that we've got a wide variety of riders on here: men, women, some with disabilities or other health issues, but also an awful lot (probably the majority) who are riding trikes just for the fun of it although they could easily be on two wheels still. I am sure that most of our membership is in their 50s and 60s, but of course we have members that span a very wide age range.