Subsequent contributions to the fund will be determined on a yearly basis by comparing the premium cost of full fire insurance coverage for all county buildings to the premium cost for fire insurance coverage with a $250,000 self-insurance retention for all county buildings. The difference between these two figures will be the annual contribution to the fund. Subsequent annual contributions will be made until the first year that the total of the fund, including principal and interest, is equal to or exceeds $250,000. (Added by Ord. 80-103 § 1, Nov. 26, 1980).