In order that each college treasurer appointed in accordance with RCW
28B.50.142 may make vendor payments, the state treasurer will honor warrants drawn by each community and technical college providing for one initial advance on July 1 of each succeeding biennium from the state general fund in an amount equal to seventeen percent of each institution's average monthly allotment for such budgeted biennium expenditures as certified by the office of financial management, and at the conclusion of each such initial month, and for each succeeding month of any biennium, the state treasurer will reimburse each institution for each expenditure incurred and reported monthly by each college treasurer in accordance with *chapter
43.83 RCW: PROVIDED, That the reimbursement to each institution for actual expenditures incurred in the final month of each biennium shall be less the initial advance.