(a) In addition to the per diem paid by the state pursuant to the general law, the members of the Baldwin County Board of Equalization shall receive a supplement in an amount sufficient to bring the per diem to one hundred fifty dollars ($150) for the years 2008 and 2009, including any days the board has met in 2008 prior to April 8, 2008, and one hundred dollars ($100) thereafter. The board members shall be allowed mileage after the annual allowance set by general law has been exhausted. The mileage shall be at the same rate as that paid to state employees for official business. Any mileage paid pursuant to this section shall be for mileage incurred in any necessary business directly related to the duties of the office, including, but not limited to, the inspection of property and travel between the member's residence and the location set for hearing taxpayer protests.
(b) The additional compensation provided for by this section shall be paid on a pro rata basis by the political subdivisions or funds in the county receiving ad valorem taxes by computing the percentage that the amount any political subdivision or fund in the county receives bears to the total local ad valorem taxes.