851.8. Where, at a particular time, the fair market value of property transferred by an insurer to a segregated fund results in both an increase at that time in the portion of the insurer’s reserves in respect of a segregated fund policy that vary with the fair market value of the property of the fund and a decrease in the portion of those reserves that do not so vary, the amount of that increase is deemed, for the purposes of computing the income of the insurer, to be a payment made by it in accordance with the terms and conditions of the policy at that time.