(f) Non-highway diesel motor fuel rate.
- (1) The basic non-highway diesel motor fuel rate shall be nine and three-tenths cents per gallon.
- (2) Every year as of January first the non-highway diesel motor fuel rate then in effect on the immediately preceding December thirty-first shall be adjusted as follows: Such rate shall be multiplied by a fraction the numerator of which is the sum of the monthly producer price index (unadjusted) published by the bureau of labor statistics of the United States department of labor for the category of commodities designated "refined petroleum products" for the twelve consecutive months ending with the month of August of the immediately preceding year and the denominator of which is the sum of the monthly producer price index (unadjusted) published by the bureau of labor statistics of the United States department of labor for the category of commodities designated "refined petroleum products" for the twelve consecutive months ending with the month of August in the year prior to such immediately preceding year, provided, however, that the adjusted rate shall not increase above or decrease below the rate in effect on the immediately preceding December thirty-first by more than five percent.
- (3) Notwithstanding any other provision of this article, non-highway diesel motor fuel which is "manufacturing gallonage," as such term is defined in subdivision (m) of section three hundred of this article, shall be exempt from the measure of the non-highway diesel motor fuel component of the tax imposed under this section.