(2) Any assessor who is unable to certify the current assessed value for any joint district lying partially in the county by September 25 shall, with the cooperation of the Department of Revenue, estimate as closely as practicable the assessed value of that district for the purpose of apportioning the ad valorem property taxes of the joint district in the current year as equitably as is possible. The estimate shall be completed and certified to the assessor or assessors of the other counties on the fifth business day after September 25 and shall be used as the basis for the apportionment required by this section. [Amended by 1953 c.194 §2; 1963 c.274 §1; 1967 c.199 §1; 1971 c.482 §1; 1977 c.892 §38; 1979 c.438 §5; 1981 c.804 §86; 1985 c.613 §5; 1991 c.459 §223; 1997 c.541 §254; 1999 c.1078 §69; 2003 c.621 §94]