(a) This section shall not apply to industrial policies to be issued on or after the operative date of Section 27-15-78, as defined therein.

(b) The adjusted premiums and present values referred to in this article for all policies of industrial insurance shall be calculated on the basis of the Commissioners 1961 Standard Industrial Mortality Table. All calculations shall be made on the basis of the rate of interest specified in the policy for calculating cash surrender values and paid-up nonforfeiture benefits; provided, that such rate of interest shall not exceed three and one-half percent per annum; provided further, that a rate of interest not exceeding four percent per annum may be used for policies issued on or after August 23, 1976, and prior to July 30, 1979, and a rate of interest not exceeding five and one-half percent per annum may be used for policies issued on or after July 30, 1979; provided, however, that, in calculating the present value of any paid-up term insurance with accompanying pure endowment, if any, offered as a nonforfeiture benefit, the rates of mortality assumed in the case of industrial policies, may not be more than those shown in the Commissioners 1961 Industrial Extended Term Insurance Table; provided further, that, for insurance issued on a substandard basis, the calculation of any such adjusted premiums and present values may be based on such other table of mortality as may be specified by the insurer and approved by the commissioner.