There's no way to know, but I imagine it cannot be that high.  The overwhelming majority of a site's users will have 0 interaction with the community, period.  I would not be surprised if the "queue" represented only 10-20% of the notifies.  For the older cards (think the 3080 FTW3), I would expect it to be naturally lower due to the fact that the queue system was not announced at the time and a lot of users simply were unaware of it when they hit the button initially.