For the purpose of calculating the biennial budget request and judicial salaries as well as the number of judicial positions required in the circuit court, the supreme court shall establish and revise as needed a weighted case value, relating the judicial time required for each type of case included in the court’s jurisdiction, which when multiplied by the caseload of each court will produce the number of weighted case units for that court. Any revisions to the weighted case values shall be approved by the fiscal committee of the general court. The number of weighted case units shall be calculated by the administrative office of the courts in July of each year, using caseload statistics for the preceding 12-month period. Said weighted case units shall serve as the basis for determining the salary of part-time judges for the next calendar year.