Gates has credited the generosity and extensive philanthropy of David Rockefeller as a major influence. Gates and his father met with Rockefeller several times, and their charity work is partly modeled on the Rockefeller family's philanthropic focus, whereby they are interested in tackling the global problems that are ignored by governments and other organizations.[98] As of 2007, Bill and Melinda Gates were the second-most generous philanthropists in America, having given over US$28 billion to charity;[99] the couple plan to eventually donate 95 percent of their wealth to charity.[100]