The contingent expenses of the Prosecuting Attorney for the Fourteenth Judicial District shall be limited to the sum of seven thousand eight hundred dollars ($7,800) per annum, to be paid quarterly and to be borne by the counties of the district as follows:
(1) Baxter County ..................… (36% by population) ..................… $2,808;
(2) Boone County ..................… (36% by population) ..................… 2,808;
(3) Marion County ..................… (16% by population) ..................… 1,248; and
(4) Newton County ..................… (12% by population) ..................… 936.