(a) Where there is a reduction in assessments on State lands as defined in section 545 of the Real Property Tax Law, a transition assessment shall be computed as follows:

1. (1) The prior roll's approved assessments for parcels on the current roll shall be added together by taxing unit. That sum shall be multiplied by the adjustment index for the prior roll, and by the change in level of assessment for the current roll where such change is two percent or more.
2. (2) The prior roll's assessments for parcels acquired subsequent to the prior roll shall be added together by taxing unit. That sum shall be multiplied by the change in level of assessment for the current roll where such change is two percent or more and that product shall be added to the amount computed in paragraph (1) of this subdivision.
3. (3) Any reduction in assessments from the prior to the current roll for parcels still on the current roll shall be determined by subtracting, by taxing unit, the sum of the current roll's approved assessment from the sum of the prior roll's assessments adjusted as described in paragraph (2) of this subdivision (the difference cannot be less than zero).
4. (4) Where there was no transition assessment for a taxing unit in the prior year, the transition assessment is equal to the reduction in assessments, if any, determined in paragraph (3) of this subdivision.

5. (5) Where there was a transition assessment for a taxing unit in the prior year:

   1. (i) The prior roll's transition assessment shall be adjusted to the current roll by first multiplying by the adjustment index, and then by the change in level of assessment on the current roll where it is two percent or more.
   2. (ii) The total taxable assessed value for the taxing unit on the prior roll shall be multiplied by the change in level of assessment for the current roll where it is two percent or more.
   3. (iii) This product shall be multiplied by two percent.
   4. (iv) This amount shall be subtracted from the adjusted prior year's transition assessment determined in subparagraph (i) of this paragraph (the difference cannot be less than zero).
   5. (v) The amounts obtained in paragraph (3) and subparagraph (iv) shall be added.
6. (6) The transition assessment is equal to the amount computed in paragraph (4) or (5) of this subdivision, rounded to the nearest $10, except that a transition assessment is not established where it would be less than $50.

(b) Where the provisions of section 545 of the Real Property Tax Law require a transition assessment due to acquisition by the State, a transition assessment shall be computed as follows:

1. (1) If no transition assessment was established for the prior roll:

   1. (i) Where it appears that a transition assessment is required, or upon receipt of a written request from the appropriate taxing unit, the percentage of real property acquired on the roll preceding the prior roll shall be computed by taxing unit by dividing the total taxable assessed value of the property acquired by the total taxable assessed value of the taxing unit. The taxing unit shall be eligible for a transition assessment if this percentage is two percent or more.
   2. (ii) For each taxing unit, the transition assessment is equal to the total taxable assessed value on the prior roll of the property acquired multiplied by the change in level of assessment for the current roll where it is two percent or more.

2. (2) If a transition assessment was established for a taxing unit for the prior roll:

   1. (i) The prior roll's transition assessment shall be adjusted to the current roll by multiplying it by the adjustment index and the change in level of assessment on the current roll where it is two percent or more.
   2. (ii) The total taxable assessed value on the prior roll of any acquisitions of real property by the State which become exempt upon the current roll as provided in section 545 of the Real Property Tax Law shall be adjusted by multiplying this amount by the change in level of assessment on the current roll where it is two percent or more.
   3. (iii) The amounts obtained from subparagraphs (i) and (ii) of this paragraph shall be added.
   4. (iv) The total taxable assessed value for the taxing unit on the prior roll shall be multiplied by the change in level of assessment for the current roll where it is two percent or more.
   5. (v) This value shall be multiplied by two percent.
   6. (vi) This amount shall be subtracted from the amount determined in subparagraph (iii) of this paragraph. Where the result is negative, the result is set equal to zero.
3. (3) The transition assessment is equal to the amount computed in paragraph (1) or (2) of this subdivision, rounded to the nearest $10, except that a transition assessment is not established where it would be less than $50.