S.C. Code § 59-71-570
If the annual principal payment on account of outstanding bonds be less than five per cent of the aggregate of all bonds outstanding, there shall be placed in the sinking fund hereby established for the retirement of State school bonds such sum as is the difference between five per cent of the outstanding State school bonds and the amount retired by way of principal of such outstanding bonds during such year. The sinking fund shall be duly apportioned between debt existing by reason of borrowings for advances to the school districts or operating units of the several counties and debt existing by reason of borrowings to defray the cost of acquiring school bus equipment, in the proportion that each bears to the total of State school bonds outstanding.
Notwithstanding the preceding paragraph, the remaining balance in the Sinking Fund as of July first, 1981, shall be remitted to the General Fund of the State.
S.C. Code § 59-71-570