§ 1905. Commissioner adjustments for assessment rolls completed prior
to nineteen hundred ninety. 1. Certification. (a) Not later than the
sixth assessment roll following the first assessment roll for which the
same homestead base proportions and non-homestead base proportions are
effective in any approved assessing unit or eligible non-assessing unit
village and not less than once in every three subsequent years, the
commissioner shall certify to the chief executive officer of such
approved assessing unit or eligible non-assessing unit village and to
the appropriate fiscal officer of each county and school district in
which such approved assessing unit is included, adjusted homestead base
proportions and adjusted non-homestead base proportions. The
commissioner shall also certify to the executive officer of such
assessing unit or eligible non-assessing unit village the current
percentages determined pursuant to subdivision three of this section and
used in calculating such proportions. Such certifications shall be made
no later than thirty days prior to the last date provided by law for the
levy of taxes in each such approved assessing unit, eligible
non-assessing unit village, county or school district.

(b) If it is made to appear to the commissioner by a statement of the
assessors of an approved assessing unit, subscribed and affirmed by them
as true under the penalties of perjury, that there has been a change in
excess of ten percent in the percentage that the estimated taxable
market value of the homestead class constitutes of the total estimated
taxable market value of all real property in such assessing unit or
eligible non-assessing unit village or in any portion thereof since
certification of the most recent homestead base proportions and
non-homestead base proportions or adjusted homestead base proportions
and adjusted non-homestead base proportions, the commissioner shall
certify adjusted homestead base proportions and adjusted non-homestead
base proportions and current percentages for such assessing unit,
eligible non-assessing unit village, or portion thereof in accordance
with the provisions of this section.

(c) In the case of an approved assessing unit which has completed a
revaluation prior to the effective date of this section, the
commissioner shall certify adjusted homestead base proportions and
adjusted non-homestead base proportions and current percentages for the
first roll to which the provisions of section nineteen hundred three of
this article shall apply.

2. Base percentage. The commissioner shall compute for each such
approved assessing unit or eligible non-assessing unit village and for
each portion thereof the percentage that the estimated taxable market
value of each of the homestead class and non-homestead class constitute
of the total estimated taxable market value of all real property. Such
base percentage shall be computed on the basis of the assessed
valuations on the first assessment roll containing the revaluation or
update which is the basis for the certification or recertification of
such assessing unit as an approved assessing unit, except that:

(a) in the case of approved assessing units which completed
revaluation programs prior to the effective date of this section, such
base percentage shall be computed on the basis of the first assessment
roll which incorporated such revaluation;

(b) in the case of eligible non-assessing unit villages, such base
percentage shall be computed from the assessments on the village portion
of the first town assessment roll containing revaluation assessments and
used for the levy of village taxes; and

(c) in the case of recertified approved assessing units which adopt
local laws pursuant to subparagraph (ii) of paragraph (a) of subdivision
two of section nineteen hundred three of this article, such base
percentage shall be computed from the assessed valuations on the first
assessment roll containing the update which is the basis for
recertification as an approved assessing unit.

3. Current percentage. (a) In each year in which the commissioner
completes a market value survey which uses a base year assessment roll
later than that used in subdivision two of this section, it shall
compute for such base year assessment roll percentages as prescribed in
subdivision two of this section.

(b) In the case of an approved assessing unit which has completed a
revaluation program prior to the effective date of this section, for the
purpose of paragraph (d) of subdivision one of this section such
percentages shall be computed on the basis of the assessed valuations on
the assessment roll which is the basis of the certification of such
approved assessing unit.

4. Additional market value surveys. In the event that no market value
survey as may be required to comply with the provisions of this section
is otherwise available, the commissioner shall revise an existing survey
or complete an additional survey in conformance with the requirements of
this section.

5. Computation of adjusted homestead base proportions and adjusted
non-homestead base proportions. In each year in which it is required to
compute a current percentage pursuant to subdivision one or three of
this section, such commissioner shall compute the adjusted homestead
base proportion and adjusted non-homestead base proportion as follows:

(a) Divide the current percentage of each of the two classes which are
described in subdivision two of this section by the base percentage of
each such class.

(b) For each such class, multiply the result from paragraph (a) of
this subdivision by the proportion established in accordance with
subdivision two of section nineteen hundred three of this article. (c)
Sum the products obtained in paragraph (b) of this subdivision and
divide the product for each such class by such sum. The result for the
homestead class is the adjusted homestead base proportion and the result
for the non-homestead class is the adjusted non-homestead base
proportion.

6. The provisions of this section shall apply to assessment rolls
completed prior to nineteen hundred ninety.