The better question would be if there are a substantial number of Americans left in that city. The descendants of the 19th and early 20th Century immigrants who gave New York its character and urban culture are mostly in the suburbs or in the rest of the country.
I'm in NYC. It's an interesting phenom. A lot of the children of the parents/grandparents who moved to the burbs are now moving back.
There are also a lot of new types of immigrants. Africans, South Americans, and, of course, the euro-trash.