I'm probably in the middle of the stat myself and know people from both sides. My first thought was also that a lot of parents and children visit libraries almost daily and pupils and students visit libraries on school breaks and after school alone or with friends.

On one hand, you have a lot of busy and tired adults and a lot of old people that might not use libraries (often), but you also have the massively active younger demographics. I don't know how that would balance out and how the stats were counted. Maybe they fit somehow.