(a) All bonds or other evidences of debt having a fixed term and rate held by any life insurance company, assessment life association, or fraternal beneficiary association, authorized to do business in this state, may, if amply secured and not in default as to principal and interest, be valued as follows:
(1) If purchased at par, at par value; or
(2) If purchased above or below par, on the basis of the purchase price adjusted so as to bring the value to par at maturity and so as to yield in the meantime the effective rate of interest at which the purchase was made.
(b) The purchase shall in no case be taken at a higher figure than the actual market value at the time of purchase.
(c) The commissioner shall have full discretion in determining the method of calculating values according to subsection (a).