Charitynavigator and guidestar have datasets. Most websites have you pick a charity and then give you metrics to judge by rather than picking a metric. But they indicate for a non profit with revenue between 10-50M (mozilla foundation is 30M I think?) usually has compensation for the leader between 180k and 350k.

Their annual revenue is over 10x that. It usually is around 500mill annually, currently down to around 400mill.

That is the corporation, not the foundation right? Over 100M it should be less than 1% so as much as 4M if it is 400M.