单项选择题

HOUSEHOLD DISCRETIONARY INCOME BY HEAD OF HOUSEHOLDS AGE-GROUP
Head of Household’s Age-Group(in years)	Number of Households (in thousands)with Discretionary Income	Percent of Households with discretionary Income	Average* Household	Average* Discretionary Income per Household
15 to 24 25 to 29 30 to 34 35 to 39 40 to 44 45 to 49 50 to 54 55 to 59 60 to 64 65 to 69 70 and older	972 2，646 3，41 9 3，31 9 2，605 2，299 2，008 2，252 1，848 1，523 2，946	18.7% 27.4 31.5 33.0 30.5 33.4 31.8 35.0 28.8 25.0 22.8	$30，124 36，618 40，067 43，585 47，891 49，968 49,079 44，906 44，262 38，968 32，344	$7，790 9.130 10.919 12.405 13.999 14.448 13.550 14. 584 14.356 12.921 11.015
All age Groups	25，869	28.9%	$4l，940	$12，332

*Based on households with discretionary income．

For which age—group was the percent of households with discretionary income most nearly equal to 。（）

点击查看答案&解析