It is very difficult to say with any certainty because it varies drastically from one hour to the next. Friday/Saturday evenings are the busiest times of the week and therefore simply due to the amount of people you’re going to come across more younger guys, but also Monday/Wednesdays are pretty good with the reduced price/daytime visits.
I’m 23 myself and I’d say 90% of the time I’m one of the youngest people in the building, so you just have to be aware that there won’t always be someone that you’re interested in. Don’t be too disappointed. Feel free to contact me if you like, kik is BM35X