Sean, that's a great question. I pulled the data by scouring through my copy of the 2013 register of alumni. I don't believe it distinguishes between regular promotions and tombstone. I'll do some research on this. Thanks for bringing that to my attention.
Claude, in your table of ranks achieved, does this include tombstone promotions? If so, it could account for the large number of rear admirals.
Sean, that's a great question. I pulled the data by scouring through my copy of the 2013 register of alumni. I don't believe it distinguishes between regular promotions and tombstone. I'll do some research on this. Thanks for bringing that to my attention.