On and after May 3, 1990, and upon approval by the county governing body of a resolution of authorization, the tax assessors, tax collectors, revenue commissioners, license commissioners, or other officials whose primary duty is assessing and/or collecting ad valorem taxes in the various counties of this state, shall be compensated by an annual salary, each of such officials to receive as a minimum, except as hereinafter provided, an annual salary in the amount specified by the following schedule:

Provided, however, that in all counties wherein an elected assistant tax assessor or assistant tax collector has been or may hereafter be established by law to function separate and apart from the office of tax assessor or tax collector in such counties, the salary for such elected assistant officials shall be 90 percent of the salary established herein for the tax assessor or tax collector in such counties. Provided further, that in all counties wherein the offices of tax assessor and tax collector have been or may hereafter be combined, the official holding such combined office, by whatever title, shall receive a minimum annual salary of $10,000 greater than the minimum prescribed for his county in the above schedule. The salary for such officials in each of the various counties of this state shall be determined according to the above specified schedule based upon the 1980 federal decennial census. The salaries, as above determined, shall be paid on a pro rata basis out of the money collected each tax year into the general fund of each respective county of the state, and thereafter paid from said fund to such officials in equal installments. The pro rata share of the officials' salaries to be paid by each fund or agency receiving ad valorem taxes, shall be determined in each county by computing the percentage that the total collections for each fund or agency bears to the total collections of ad valorem taxes. With respect to any municipality in which that municipality's pro rata share of the officials' salaries provided for in this section is greater than the fees or commissions being paid by said municipality for assessment and collection of ad valorem taxes for the tax year immediately prior to such municipality becoming subject to the provisions of this section, the payment of such pro rata share by the municipality shall be in lieu of such fees or commissions. With respect to any municipality in which that municipality's pro rata share of the officials' salaries provided for in this section is equal to or less than the fees or commissions being paid by said municipality for assessment and collection of ad valorem taxes for the tax year immediately prior to such municipality becoming subject to the provisions of this section, the payment of such fees or commissions by the municipality shall be in lieu of such pro rata share. The pro rata share of salaries each fund or agency shall pay during the first year after implementation of this section shall be based upon the collections made during the tax year next preceding, the effective date of election to come under this section, and adjusted from year to year as may be necessary.