I wonder what the statistics would be if we lived in an environment where public nudity was both commonplace, and unremarkable.
Remember, I live in the country that produced the band known as the "Barenaked Ladies".
I spent some time in north eastern Germany last summer. It is not uncommon to go swimming on public beaches there, without any clothes. Public saunas are naturally mixed. They call it "Freie Körperkultur", or FKK.