Upon the death of any judge, who has made contributions pursuant to sections 476.515 to 476.570^*, not leaving a surviving spouse or minor children, the commissioner of administration shall pay a death benefit in a single payment to the decedent‘s estate. The death benefits shall be the total amount of all contributions made by the deceased judge pursuant to sections 476.515 to 476.570^* less any contributions previously refunded pursuant to section 476.540, and not restored, and less any benefit received pursuant to section 476.530 or 476.545.