(NEWSER) – It turns out 21% of working-age adults are rich for at least a year by the time they turn 60. That proportion has more than doubled since 1979, and it's an income group the AP calls America's fastest-growing, based on take-home pay. Made up largely of older professionals, working married couples, and more educated singles, the "new rich" are those with household income of $250,000 or more at some point during their working lives. That puts them, if sometimes temporarily, in the top 2% of earners. Even outside periods of unusual wealth, members of this group generally hover in the $100,000-plus income range, keeping them in the top 20% of earners.