I would venture to say that in the US the age is actually higher.
It is unfortunate that that average mental age of these forums appears to have plummeted since the release of the game. I miss the thoughtful, courteous (though passionate) debates of years past. Now these forums seem to be more of a never ending procession of one diatribe after another. And over a measley $40 (US) no less. Hell, I wouldn't doubt that most of those here of legal drinking age spend that in one weekend for a brief buzz at the local bar. Those not of legal drinking age drop more than that if they take a date to the movies. (I wonder how many return daily to rant at the theater owner or the movie studios when the movie wasn't what they perceived it to be or what the trailers implied? Or to the bar owner/beer manufacturer because the beer didn't really taste great and wasn't really less filling?)
/end of my diatribe