(1) Subject to subsection (3), where after consideration of an actuarial review and revaluation of the Scheme, or the part of it that has been reviewed, or reviewed and revalued, under section 41 the Minister is of the opinion that the amount of contributions paid by the State in respect of the employment concerned, by Scheme members generally or by the persons, or any class of persons, to whom paragraph (b), (c), (d), (e) or (f) of section 41(4) relates should be revised, then the Minister may by order revise the rate of contribution from the Scheme members concerned, subject to -

(a) where a rate determined on the basis of the actuarial review and revaluation would be higher than that standing provided for in this Chapter or by order under this subsection, as the case may be, the revised rate shall be neither higher than a rate so determined nor lower than the subsisting rate, and

(b) where a rate determined on the basis of the actuarial review and revaluation would be lower than that standing provided for in his Chapter or by order under this subsection, as the case may be, the revised rate shall be neither higher than the subsisting rate nor lower than a rate so determined.