Tennis sensation Naomi Osaka has become the highest-paid female athlete in history after earning $37.4 million over the last year. According to Forbes, Osaka earned $37.4 million in the last 12 months from prize money and endorsements, $1.4 million more than Serena, setting an all-time earnings record for a female athlete in a single year. Williams, a 23-time grand slam champion, has been the...