Meh, seems dubious to me. I teach at a Catholic university, and judging form Ash Wednesday, I'd say 3/4 still "have their faith." Moreover, Barna's research shows that many people "leave church" because it is NOT giving them "enough God" and a deep enough spiritual relationship with Jesus. In short, churches aren't losing them to the secular world, but to a deeper quest for Christianity.
Finally, I think there is a natural questioning and searching that goes on at that age---having taught that age group for 30 years---and many return to the faith (which they really didn't "leave") within 10 years. About the time reality hits them.
You must be missing the Great Falling Away. It’s happening, now, even asthey attend Ash Wednesday services.