Don't know the total number obviously - but my local airport is full of ATP's who are still flying (for fun). A lot of these guys may have flown professionally during their younger years, we have a lot of ex-corporate guys who now on airplanes along with retired TWA guys. I'm one of those former 121 ATP's who'd have interest in getting back for the right situation, but that's not happening.

There may be a pilot shortage looming at some point, but right now it's just a pay shortage that keeps guys on the sidelines.