Good question, I don't know. I suspect he did quite well for himself. He was pretty fit, IIRC on his second or third dan in martial arts.
He always kept quiet about his dating, even when his mother was trying to get details from him. IME the ones who talk about sex a lot don't get much, and the ones who are reticent might be scoring freely.
i did happen to see an empty condom six -pack in the wastebasket of his student accommodation. AFAIK there is no evidence 18-19 yo women are less randy than their male counterparts.