This is actually less than the general population. Baptists also cause a disproportionate amount of crime. As far as I'm concerned, an atheist has more justification for these beliefs. The religious also take an illogical position on the death penalty. As an atheist, I am more justified to push for tough penalties or death right here and now.
Christian morality is poor morality.
Sure, the stuff they teach every week is squeaky clean, but the Old and New Testaments would indicate otherwise. Thus saith the LORD God of Israel, Put every man his sword by his side, and go in and out from gate to gate throughout the camp, and slay every man his brother, and every man his companion, and every man his neighbour. And there came forth two she bears out of the wood, and tare forty and two children of them. But all the women children, that have not known a man by lying with him, keep alive for yourselves. Basing morals on societal standards may be changing, but it is relevant and temporarily absolute.