Its still interesting there's no one under 18 or over 33 who's voted, and only one 30-33 year old. It looks like anime and manga is an interest for people in their late teens and their twenties, especially their late teens and early twenties.
I guess this fits with the interest in anime and manga among university students, but I'd have expected the next largest demographic after them to be people aged 12-17. And I would have expected at least one or two votes from people over 33, instead, there's only one vote from someone in their 30s.