Among the various headings one could explore on the top of the Hub page, there once was a heading called "Hubbers" which listed all of them, down to many who had never published anything and had no score whatsoever.
I can't seem to find that heading with the actual list, but when I've been able to do so, there were many thousands of Hub members, though those who were really active were relatively MUCH fewer. Members were listed by score, and those with scores of 100 were only about a dozen out of all the members at that time, with gradual increases in numbers of Hubbers as scores decreased. However, those with scores in the 90s still represented relatively few compared to the entire membership.
Wish I could supply a more current and exact answer. Hopefully someone else will be able to!