For the purpose of distributing state-shared revenue to counties and municipalities based upon the population as disclosed by the last federal decennial census, the effective date of such federal decennial census for counties shall be the first day of the month next following the date on which the federal bureau of the census releases the final population figures for all Tennessee counties, and the effective date for municipalities shall be the first day of the month next following the date on which the federal bureau of the census releases the final population figures for all Tennessee municipalities.