It's hard to say precisely because in America we have a federal system, so it isn't necessary to warehouse New York's criminals on 5th Avenue, but the main NYC jail has 14,000 inmates (per wiki) which would be an insignificant portion of the population of the city. You can dig around on NYC.gov/doc if you want more information.

http://www.nbcnewyork.com/news/local/Ro ... 46193.html cites 55,599 as the population

Not really insignificant...

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North Lecale

You may be conflating New York state with the metropolis formerly known as New Amsterdam.