Upon termination of the commission, any remaining funds that are not required by the director to defray commission expenses shall be returned by the director upon a pro rata basis, to all persons from whom the assessments were collected unless the director finds that the amounts to be returned are so small as to make impractical the computation and remitting of the pro rata refund to the appropriate persons. If the director makes a finding that returning the remaining funds would be impractical, he or she may use the moneys in the fund to defray the costs of the office.