I want to say the total amount of "accounts" was low 3000s when I first joined or whenever they started the priority system, was about the same time. Even then I think there were some accounts that were no longer active but were still in the ranking system? Not sure how they manage that and whether those are part of the 8000 some they have now.
Sent from my Pixel 3a XL on a bullet train from Hillsboro.