253.45. Where an alteration to the roll affecting the taxable value of a unit of assessment has effect from a date, later than 1 January, comprised in the second fiscal year for which the roll applies, the last amount of abatement established for that fiscal year in respect of the unit pursuant to section 253.43 or to this section is replaced, from the date the alteration has effect, by a new amount of abatement if the latter amount is different from the former amount.
The new amount is established by performing the following operations consecutively:(1) multiplying the tax rate fixed for the second fiscal year for which the roll applies by the lesser of the taxable value of the unit on 1 January of the first fiscal year and its taxable value after the alteration;
(2) subtracting, from the product obtained under subparagraph 1, the maximum amount of tax for the second fiscal year for which the roll applies as established pursuant to the second paragraph of section 253.43.
If the difference resulting from the subtraction made under subparagraph 2 of the second paragraph is negative, the new amount of the abatement is $0.
For the purposes of the second paragraph, if section 253.43 re-applied in respect of the unit to take account of an alteration referred to in section 253.44 and the abatement in respect of the unit is not withdrawn as a result of the alteration, the taxable value of the unit on 1 January of the first fiscal year for which the roll applies and the maximum amount of tax for the second fiscal year are the value and amount established as a result of the re-application of section 253.43. If the re-application occurs after the application of this section, this section is re-applied to take account of the re-application.