(2) Net considerations: The net considerations for any annuity or pure endowment contract referred to in subsection (1) of this section shall be calculated on an annual basis, shall be such that the present value thereof at date of issue of the annuity shall equal the then present value of the future benefits thereunder (excluding any total disability benefits attached to such contracts) and shall be not less than the following percentages of the respective considerations specified in the contracts for the respective contract years: First year. . . . fifty percent
Second and subsequent years. . . .ninety percent
PROVIDED, That in the case of participating annuity contracts the percentages hereinbefore specified may be decreased by five.