; or (C) cost-of-living allowances in nonforeign areas under section 5941. (3) Limitations (A) In general During the control period described in subparagraph (B), the amount of the overtime supplement that is considered basic pay under subparagraphs (A) and (B) of paragraph (1) may not exceed the amount computed by multiplying the border patrol agent’s basic border patrol rate of pay by the percentage representing the agent’s career average of assigned overtime supplement percentages (including 0 percent for periods of time during which no overtime supplement was payable). The career average percentage shall be computed under this subparagraph without regard to the effect of the limitation on premium pay under section 5547. The premium pay limitation remains applicable in determining the dollar amount of any overtime supplement computed using the career average percentage. (B) Control period The control period referred to in subparagraphs (A) and (C) is the period beginning 3 years before the date on which a border patrol agent will meet age and service requirements associated with entitlement to an immediate annuity and ending on the last day of the individual’s career as a border patrol agent. (C) Career average percentage For purposes of subparagraph (A), a border patrol agent’s initial career average of assigned overtime supplement percentages is the average for the border patrol agent’s career before the beginning of the control period. During the control period, the career average shall be recomputed at the end of each annual period (as described in subsection (b)(1)(A)). In computing the career average percentage, any periods of service as a border patrol agent before the first day of the first pay period beginning on or after January 1, 2016, shall be included, and the agent’s assigned overtime supplement during such periods shall be deemed to be 25 percent. If the career average percentage is less than 25 percent, the precise amount of the career average percentage shall be used for purposes of this