AHV did an analysis on request of NZZ, so for the first time we have the actual percentile data (for 2021) based on all employees in Switzerland (analysis excludes self-employed people):
99.99 is not precisely published, but there were exactly 535 people earning more than CHF 3 Million.
Income is the AHV income, which is basically the gross income including everything at the time of the payout.