Take a look at the second graph in this page.
in reply to Website Users
You'll notice that out of 4263 PAUSE ids, 1819 were never used to upload anything. That's over 42% inactive accounts.
Not exactly 81%, but that's probably because a PAUSE id has to be aproved, while a perlmonks account hasn't (which is a bit scary... almost 2000 people had plans, announced them, got their ids approved and... gave up?)
But I don't think there's anything to worry, though. I have subscribed sites myself that I never got to use, has have many around here, probably.