I would think it would vary significantly based on travel patterns. I would think Golds and GGLs who routinely flew long-haul Y or PE would have much higher rates than those always sitting in J.

I have never been op-up'ed short haul. I once received an op-up from PE to J on LHR-JFK. Note this is the only time I have ever been in longhaul Y or PE when going to the airport - all other times J or F. Never been upgraded J to F though.