More of America’s billionaires are starting to give away their fortunes even before they reach middle age, according to The Chronicle of Philanthropy‘s annual Philanthropy 50 rankings. But even with $1.1-billion in new gifts from billionaires under 40, mega-philanthropy last year remained below levels seen before 2007.

To learn how much each donor gave last year, where the money went, biographical information and more, check out The 50 Most Generous Donors of 2012.