@jetton
I'm concerned the 80+ category lacks the granularity to distinguish between those in their 80s-90s and those who have been around since... let's say 1518, pretending to croak every once in a while, leaving all their possessions to kids who've been corpses for years, and assuming their identities...
Purely hypothetically, of course. Not worth losing one's head over.
@imalcolm
A salient point. Perhaps I need a follow-up survey expanding that category.
You seem to show great familiarity with how this is done and 1518 does seem decidedly specific.