At some schools (including my alma mater) the registrar publishes grade distributions by course and by section. As 5 percent, Bs 30 percent, Cs 50 percent and so forth. It allows students to see which instructors are tougher than others. I don’t recall if the number of students who dropped or withdrew was included. They are still publishing them last I looked (a year or so ago). It saved me from a weed out course or two back when they were in big paper books. Now they are online.
And at the risk of another ancient story to annoy everyone - our grades were posted by social security number back in the late 80s and early 90s.