If one or more political subdivisions of the State participate in the costs of carrying out the child support enforcement activities during any particular period, each such subdivision shall be entitled to receive an appropriate share of any federal incentive payments made to the State for such period. The exact amount of the share shall be determined by taking into account the efficiency and effectiveness of the activities carried out by the political subdivisions, and measured by a standard methodology which shall be developed by the agency, for passing through an appropriate share of its incentive payment to participating political subdivisions.