Where I live (Ireland), the convention scene is predominantly teenagers around 16/17. As I get older, I feel more out of place. I'm only 22, so I'm not old at all, but everyone else is so much more energetic and there aren't many people my age left. There are still attendees older than myself, but the number is usually in the single digits.
I watched Crunchyroll's livestream of an American convention (A-Kon maybe?), and it seemed to be a bit more diverse.
I've wanted to visit a larger convention on a visit sometime in the future, so I was wondering what the age demographic usually is for American conventions such as Anime Expo or Otakon.