Median violation points assigned by the New York City Department of Health and Mental Hygiene to the restaurants of each zip code according to nyc.gov, rounded to the nearest whole number. Cleanest and dirtiest are the zip code(s) in each borough with the lowest and highest median violation points among zip codes with twenty or more restaurants. When this resulted in a tie between three or more zip codes or when all zip codes in a borough fell above or below the city’s median score (16) such a determination was not made.