By “work for someone else” I mean “regularly perform, or depend for one’s living on performing, services to others”. People who just own companies that make money for them would count, as long as they don’t also act as CEOs. People who don’t work at all count. Mountain men count, if they still exist and aren’t supporting themselves by selling game or pelts. Figurehead monarchs may arguably count.
Is there any way to estimate the number of such people?