If the recommended cash reserves required by § 846.154(a) exceed the greater of 40 percent of the total contributions for the preceding plan year or 40 percent of the total contributions expected for the current plan year, the contributions may be reduced to fund less than 100 percent of the aggregate retention plus all other costs of the multiple employer welfare arrangement, but not less than the level of contributions necessary to fund the minimum reserves required under § 846.154(a).