Computation of a child support arrearage/debt under a Maine court order which establishes or modifies a child support obligation shall be governed by 19 M.R.S.A. §303(1), as enacted by PL 1989, c. 156 (the first paragraph of 19 M.R.S.A. §303, as enacted by PL 1969, c. 175), if the order was issued on or after October 1, 1969 and before April 17, 1990.
10- 144 C.M.R. ch. 351, § 16-13