It's a bad habit, but people (including me) often say "New York" when they mean "Manhattan". The population density of Manhattan is 70,951/sq mi (27,394.3/km2)

It's a bad habit, but people (including me) often say "New York" when they mean "Manhattan". The population density of Manhattan is 70,951/sq mi (27,394.3/km2) according to Wikipedia.