19. If the amount paid to the spouse comes from an entitlement to a pension, the pension is reduced, from the date of payment or from the date on which it becomes payable in the case of a judge 65 years of age, or 70 years of age or over, as the case may be, at the date of assessment, by the amount of pension that would be obtained on the basis of the sums awarded to the spouse at the date of assessment.