Here are the usage stats for november. But it includes during the early part where there were glitches like allowing megas from future gens, but removed those pokemon but still that could skew what pokemon was used against them. Also most importantly it's the usage from all matches, not just matches of people with high rankings so it's not necessarily showing whats the best, just what literally everyone used including completely new players.
https://www.smogon.com/forums/attachments/usage-txt.148472/ 