99.9.3.For the purposes of the plan provided for in Division II of this Act and Title IV of the Act respecting the Government and Public Employees Retirement Plan (chapter R-10), the pensionable salary for the years or parts of a year covered by the agreement is the salary the officer would have received or, for a period in respect of which salary insurance benefits apply, the salary which he would have been entitled to receive if he had not availed himself of this subdivision. The service credited is the service which would have been credited to the officer if he had not availed himself of this subdivision.