The association shall issue to each member insurer paying an assessment under the provisions of sections 376.715 to 376.758, other than class A assessment, a certificate of contribution, in a form prescribed by the director, for the amount of the assessment so paid. All outstanding certificates shall be of equal dignity and priority without reference to amounts or dates of issue. A certificate of contribution may be shown by the member insurer in its financial statement as an asset in such form and for such amount, if any, and period of time as the director may approve.