http://en.wikipedia.org/wiki/Demographics_of_Manhattan

目前的资料还没找到。根据这份资料，曼哈顿的人均所得是$42,922，以汇率6.8计，
合291,870人民币一年，也就是两万四千三百多一个月。曼哈顿最富的区，人均所得
超过 $90,000，大约是上面数字的一倍:

The median income for a household in the county was $47,030, and the median
income for a family was $50,229. Males had a median income of $51,856 versus
$45,712 for females. The per capita income for the county was $42,922. About
17.6% of families and 20.0% of the population were below the poverty line,
including 31.8% of those under age 18 and 18.9% of those age 65 or over.

Manhattan is one of the highest-income places in the United States with
a population over 1,000,000. In particular the Upper East Side, ZIP Code
10021, with over 100,000 inhabitants and a per capita income of over $90,000,
is one of the largest concentrations of extreme wealth in the entire United
States. Nevertheless, like all large cities, Manhattan does have some large
enclaves of concentrated poverty.