If you expand the definition of "children" to include people into their early 20s, and expand the definition of 'sexual abuse', you can get the statistics anywhere you want. When I was 13, I had a girlfriend who was 18. Anything we did, even holding hands, is considered 'abuse'. Once the idea 'consent is impossible for anyone under 18' is floated, adolescent sexuality is criminalized and you get to categorize all of the natural urges and activities of teenagers as rape and abuse. That helps feed into the vision most parents have of the world being filled with prolific rapists with a taste for children. In reality, pedophilia is extremely rare, almost all actual abuse is conducted by parents, and teenagers who get caught exploring and experimenting are damaged by their parents and societies reactions to them, not the act itself.