C.R.S. § 22-41-105

(1) Any amount paid as a premium for an interest-bearing obligation in excess of the amount realized upon disposition of said obligation must be recovered as a return of principal out of interest thereafter derived from the public school fund. Such recovery must be made and recorded on a systematic basis applied consistently from year to year. (2) Interest and income that is not distributed as specified in section 22-41-102 (3) on June 30 of any fiscal year becomes part of the principal of the public school fund.