; actuarial assumptions (a) Certification of funded ratios (1) In general Not later than the one-hundred twentieth day of each plan year of a composite plan, the plan actuary of the composite plan shall certify to the Secretary, the Secretary of Labor, and the plan sponsor the plan’s current funded ratio and projected funded ratio for the plan year. (2) Determination of current funded ratio and projected funded ratio For purposes of this section— (A) Current funded ratio The current funded ratio is the ratio (expressed as a percentage) of— (i) the value of the plan’s assets as of the first day of the plan year, to (ii) the plan actuary’s best estimate of the present value of the plan liabilities as of the first day of the plan year. (B) Projected funded ratio The projected funded ratio is the current funded ratio projected to the first day of the fifteenth plan year following the plan year for which the determination is being made. (3) Consideration of contribution rate increases For purposes of projections under this subsection, the plan sponsor may anticipate contribution rate increases beyond the term of the current collective bargaining agreement and any agreed-to supplements, up to a maximum of 2.5 percent per year, compounded annually, unless it would be unreasonable under the circumstances to assume that contributions would increase by that amount. (b) Actuarial assumptions and methods For purposes of this part— (1) In general All costs, liabilities, rates of interest, and other factors under the plan shall be determined for a plan year on the basis of actuarial assumptions and methods— (A) each of which is reasonable (taking into account the experience of the plan and reasonable expectations), (B) which, in combination, offer the actuary’s best estimate of anticipated experience under the plan, and (C) with respect to which any change from the actuarial assumptions and methods used in the previous plan year shall be certified by the plan actuary and the actuarial rationale for such change provided in the