N.Y. Real Prop. Tax Law § 1251

§ 1251. Establishment of special equalization ratios. The commissioner\nshall, for a city with a population of one hundred twenty-five thousand\nor more inhabitants, establish annually the ratio of the assessed\nvaluation to the full valuation of taxable real estate on the last\ncompleted assessment roll and each of the four preceding assessment\nrolls of such city in accordance with the provisions of this article.\n