The commissioners court annually may set aside from the general fund or the permanent improvement fund of the county an amount to be used to maintain or to make a permanent improvement or acquire land for the county library. The amount may not exceed 12 cents on the $100 valuation of all property:
(1) located in the county outside the municipalities that are supporting a free public library and that are not participating in the county library system; and
(2) located within the municipalities that are supporting a free public library and that have elected to become a part of the county library system.