During the course of the year to which the plan applies, the rule requires a utility to apply deferral accounting treatment to the actual costs incurred for fuel cost items. The PSCW then reconciles the difference between the forecasted and the actual, reasonable and prudently incurred fuel cost on an annual basis. After a hearing, the Commission approves a reasonable adjustment to prospective rates to implement this reconciliation. If extraordinary circumstances during the plan year cause the projected average annual fuel cost to differ materially from the forecast of the average annual fuel cost used in an approved fuel cost plan, and the projected absolute value, at current rates, of the difference between these amounts at the end of the plan year likely will be of sufficient magnitude to cause a material change to rates, the Commission may adjust rates during the plan year to avoid a reconciliation that causes a material change in rates. However, while the rule imposes no limit to the number of mid-year rate decreases the Commission may order, no utility may obtain a mid-year increase in rates more than once during a plan year.