New York Consolidated Laws, Real Property Tax Law - RPT § 1252. Manner by which ratios shall be determined

In determining ratios pursuant to this article, the commissioner shall, for the last completed assessment roll and each of the four preceding assessment rolls, determine the ratio of assessed valuation to full valuation as of the first day of January of the fiscal year for which the ratio is applicable. Each ratio shall be determined on the basis of the market value survey completed pursuant to article twelve of this chapter and for which the valuation date is the first day of January of each applicable year. In the event that a market value survey has not been completed based upon each such valuation date, the commissioner shall determine the ratios in the following manner: