From The New York Times an article on the sizing of America.
Among the findings: older men have trimmer thighs than younger men. Black women are larger than other women, but they are also most likely to have the classic hourglass figure. Sixty-four percent of women are pear-shaped, and 30 percent are “straight,” meaning they had little perceptible waist.
Nineteen percent of men are “portly,” and another 19 percent have “lower front waists,” meaning, the researchers said, they had to look under a belly to find the waist. Men over 45 are most likely to have potbellies, women over 36, bigger hips (though black women older than 55 have smaller hips than those 46 to 55).
An interesting article; check out how clothing sizes are changing.