(1)Where for any accounting year, the allocable surplus exceeds the amount of maximum bonus payable to the employees in the establishment under section 11, then, the excess shall, subject to a limit of twenty per cent. of the total salary or wage of the employees employed in the establishment in that accounting year, be carried forward for being set on in the succeeding accounting year and so on up to and inclusive of the fourth accounting year to be utilised for the purpose of payment of bonus in the manner illustrated in the Fourth Schedule.