Wish I had gone to school where you did. We all had to change in a big locker room with just benches, and had to take a full shower in an open shower room after class. Like another person said, it was part of our grade, and our showers were recorded. The only exceptions were for your monthly period, when you could take a partial, and that was tracked. There was one bathroom stall, and the teacher watched to ensure that people weren't using it as a changing room so that it could be used by those who needed to use the bathroom. It was bad enough as it was; I wouldn't have wanted to have to change and shower with individuals of the opposite sex.
*Snip*