The Oregon Department of Administrative Services shall determine and may at any time redetermine which state funds or appropriations shall be assessed a reasonable share of governmental service expenses. In determining or redetermining the funds that shall be so assessed:
(1) A fund consisting of moneys the use of which is restricted by the Oregon Constitution shall be assessed only those governmental service expenses ascertained as being necessarily incurred in connection with the purposes set forth in the Oregon Constitution.
(2) Trust funds shall be assessed only those governmental service expenses ascertained as being necessarily incurred in connection with the purposes for which the trust fund was established.