5(1)Where a payment in respect of a bonus or retroactive increase in remuneration is made by an employer to an employee whose total remuneration from the employer, including the bonus or retroactive increase, may reasonably be expected not to exceed $5,000 in the taxation year of the employee in which the payment is made, the amount to be deducted or withheld by the employer from the payment is the relevant fraction of fifteen per cent of that payment.