You're all obsessed with age boundaries and sexual trends, like the sex age minimum is 16, when if there were no boundary you'd probably be out shagging 15 year olds. Your opinions on people change completely when they climb over the age fence, mark my words.
edit: the age is set for the age of mental maturity, if it were sexual maturity it'd be 21. Most people aren't mentally prepared for sex at the age of 15, though 16 is the average age. If you're going out with somebody, I know a 16 year old with a 14 year old, they have sexual relations because they both know they're mature enough to do it.