"9,692.31 per annum with effect from2nd May 1988 .
" (3) Where the total amount of any wages that are paid on any occasion by an employer to any worker employed by him is less than the total amount of the wages that are properly payable by him to the worker on that occasion (after deductions) then, except in so far as the deficiency is attributable to an error of computation, the amount of the deficiency shall be treated for the purposes of this Part as a deduction made by the employer from the worker's wages on that occasion."