The statistics are quite clear and are easily found by those who look. Homosexuality is no more inherently sinful than heterosexuality. Comparing a person's sexual orientation with violent crime / rape/ murder is not a good idea, they are quite different things.
One issue worth considering is just what we mean when we say "homosexuality".
If we're talking about desires for members of the same sex then I don't see that as being any more sinful than me, as a heterosexual man, having desires for women other than my wife. What matters is what we do with those desires.
If we're talking about a physical homosexual relationship then it takes a more detailed Scriptural study to determine whether it is sinful or not. Statements like "it's not sinful" with nothing to back it add no more to a discussion than the people who quote selected verses from Leviticus while ignoring most of the rest of Leviticus.
My current understanding, based on the OT and NT (especially Romans 1) is that a physical homosexual relationship is sinful (although as with other things I'm open to anyone who wants to present a coherent Scriptural case that I'm wrong). That said the fact that something is sinful doesn't mean children shouldn't be taught about it in schools. It would be a sad state indeed if we were to try and censor discussion just because we found the subject matter distasteful, even abhorrent. Ultimately it comes back to the notion that a publicly funded education system needs to cater for the requirements of the public, regardless of whether they share our particular faith.
There's certainly an inconsistency in play, as Josiah posted further back, where some people get to express their opinions under the guise of "tolerance" but dissenting opinions are not tolerated by the very people who preach tolerance. But the way to address that is to tolerate all opinions, not flip which opinion is allowed to be expressed.
