将这个数字与CBO所测算的50%左右的收益相加，意味着实际中位家庭收入在过去30年的年增长率接近2.5 % 。
And combining that with the CBO estimate of a gain of about 50% would imply that the real income of the median household is up nearly 2.5% a year over the past 30 years.