In college, why is it so hard to find a girl who isn't promiscuous and getting around? Why is sin so common?

As a college student and a Christian man, every girl I have met at college is promiscuous and getting around. Even the Christian girls that I have met at church fit into this category. This type of behavior from men and women disgusts me and I'm wondering how I can stay sane in a town and college of sin and find a woman who is faithful and true?