424.17  Reduction of rentals with excess earnings.--If in any calendar or fiscal year the gross receipts of any company formed hereunder should exceed the payments or charges specified in s. 424.08, the sums necessary to pay dividends, interest accrued or unpaid on any stock or income debentures, and the authorized transfer to surplus, the balance shall be applied to the reduction of rentals, unless the board of directors with the approval of the Department of Community Affairs deems such balance too small for the purposes.