Bill Gates, 65, founded Microsoft in 1975 with Paul Allen. His net worth stands at an estimated $130.5bn, according to Forbes, and he has donated $35.8bn worth of Microsoft stock to the couple’s foundation. He announced last year he would be stepping down from Microsoft’s board to focus full-time on his work as the foundation’s co-chair. Melinda Gates, 56, serves as the foundation’s co-chair and is the founder of Pivotal Ventures, an investment and incubation company that focuses on advancing the interests of American women and families. Launched in 2000, the Bill & Melinda Gates Foun...