I just reconnected with a dozen or so from my teenage hall a few years ago, and we are talking 1970-1975 era. Of the ones that we know of, 60-70% left, and left way before me. I think of the ones that are still in, I think a good percentage of their kids and grandkids have left.
I saw several elders at a memorial service a month ago, we were all teenagers together. I am telling you, they looked so weary, and tired. They looked beat up, not kidding. I know they know it's BS, and don't know what to do about it.