+7
Worth noting that while this probably tells us something about the age ranges here, there's a lot of selection bias problems.
Forums are infamous, for example, for:
a) Only a tiny fraction of visitors joining and
b) Nearly all posts coming from a tiny fraction of those who join
So you're already two levels "deep" when you're talking about forum regulars, and then adding to that people who notice and bother to respond to polls like this, and it's hard to say exactly how representative it is. My feeling is this poll probably skews a little older than the membership as a whole, which in turn skeps significantly younger than the visitors as a whole. Whether that even matters or not is another question.
I do think this place is probably older than most places on the Internet though (though maybe not much older than most forums, which are an older form of social media already and are a little alien to younger people, still). And I think its makeup and its general level of discourse are probably connected.