Notwithstanding the provisions of sections 38a-663 to 38a-696, inclusive, whenever the fund assesses insurers in accordance with sections 38a-894 to 38a-898, inclusive, each insurer shall charge an additional premium on every property insurance policy issued by it insuring property in this state the effective date of which policy is within the three-year period commencing ninety days after the date of assessment by the fund. The amount of the additional premium shall be calculated on the basis of a uniform percentage of the premiums on such policies equal to one-third of the ratio of the amount of an insurer’s assessment to the amount of its direct earned premiums for the calendar year immediately preceding the year in which the assessment is made, such that over the period of three years the aggregate of all such additional premium charges by an insurer shall be equal to the amount of the assessment of such insurer. The minimum additional premium charge on a policy may be one dollar, and any other additional premium charge may be rounded to the nearest dollar. Any funds collected from these additional premium charges by an insurer, in excess of any assessment, shall be transmitted forthwith to the fund.