A municipal utility whose property tax assessment for the 1998 assessment year was adjusted by the department of revenue to include depreciation and whose property tax assessment for the 1997 assessment year did not include depreciation in determining its assessment shall be entitled to file a property tax adjustment form provided by the department. The tax adjustment form shall be filed by July 1, 1999. The tax adjustment form shall include an adjusted centrally assessed property tax computation determined by multiplying the centrally assessed property tax which was payable in the fiscal year beginning July 1, 1998, based upon valuation determined for the 1997 assessment year allocated to electric service and natural gas service by the percentage of adjustment for depreciation made by the department for the 1998 assessment year. The adjusted centrally assessed property tax allocated to electric service and natural gas service shall be used to determine the replacement delivery tax rates in accordance with sections 437A.4 and 437A.5.