You just don’t know if “ doing it in the butt have exploded since 1995” has really increased. People are not going to talk about sexual behavior in a questionnaire.
Even a casual knowledge of culture would allow you to know homosexuality has exploded since the 90s. And when I was young I literally never heard of a young female doing it up the butt. It was so deranged nobody even heard of it.
Now even a cursory glance at the under 30 culture would show you it has become a norm for the young deviants.