The salary for the office stenographer for the Prosecuting Attorney of the Fourteenth Judicial District shall be set at the sum of nine thousand dollars ($9,000) annually, to be paid in equal monthly installments and to be borne by the counties of the district as follows:
(1) Baxter County (36% by population) $3,240;
(2) Boone County (36% by population) 3,240;
(3) Marion County (16% by population) 1,440; and
(4) Newton County (12% by population) 1,080.