For the purposes of § 23-9-370 and to defray the expenses thereof, each county treasurer shall pay over to the treasurer of the South Carolina State Firemen’s Association the sum of five percent of the gross proceeds received annually by each county, town, or unincorporated community from the one percent tax on fire insurance allocated to the city, town, or community. The sums so paid must be expended for the sole purpose of the betterment and maintenance of skillful and efficient fire departments within the county.