Percentile

Maybe this page can answer you question: https://www.chess.com/leaderboard/live/rapid

Percentile is always changing slightly as some chess players become inactive and other players join the community. However, just as my intuitive estimate for percentile: it would be something like:
2000 rating: 99.8%
1800 rating: 99%
1500: 95%
1300: 80%
This is because the "average" is skewed based on the fact that there are WAY more beginners in the chess community than there are titled players. This video of mine shares a little about it: