For the 35 years of playing D&D on and off I have DM'd probably 90% of that time. I have run a character for maybe two times in the last 10 years. A player in my current game whose been playing for about 2 years has expressed interest in DMing so maybe, hopefully, that'll work out.
... It fluctuates. When I was involved with 4e Organized Play, I was primarily DMing, because I got to keep all the material. Nowadays, I play in 2 (possibly 3) campaigns and DM 1 (though if I end up quarantined much longer I might start a 2nd).
~90% DM for almost 30 years. (And by "DM" I mean not just Dungeon Master but GM, Storyteller, Keeper and so on, and so on, even though this is a D&D forum, obviously.)