Adjustment Period is 1 to 4 years determined as follows for a rate area:

1 year if Actual Costs exceed Actual Receipts by less than five percent;

2 years if Actual Costs exceed Actual Receipts by five percent or more but less than fifteen percent;

3 years if Actual Costs exceed Actual Receipts by fifteen percent or more but less than twenty-five percent; and

4 years if Actual Costs exceed Actual Receipts by twenty-five percent or more.