20. For the purposes of sections 17 and 18, the amount of pension that would be obtained on the basis of the sums awarded to the spouse at the date of assessment is determined in accordance with the actuarial method and assumptions provided for in section 6. That amount of pension is presumed applicable at the date of assessment.
The amount of pension obtained under the first paragraph is indexed in the same manner as the retirement pension or in the manner it would be if it were being paid at the date of assessment, from 1 January following that date to 1 January of the year during which that amount of pension begins to apply.
Where applicable, that amount of pension is presumed applicable for the residual period applicable to the retirement pension in accordance with section 47 of the Act respecting the conditions of employment and the pension plan of the Members of the National Assembly (chapter C-52.1), as it read on 31 December 1991, to the extent that that section applies to the annual retirement pension of the former Member. However, if the retirement pension of the former Member was replaced by a life annuity with continuity in favour of the surviving spouse under section 52 of the Act respecting the conditions of employment and the pension plan of the Members of the National Assembly, as it read on 31 December 1991, the amount of pension mentioned in the first paragraph is adjusted in the same manner as the retirement pension in accordance with that section.
The amount of pension obtained under the first and second paragraphs is increased by 0.50% per month, calculated for each month between the date of assessment and the date at which that amount of pension begins to apply if the pension was being paid at the date of assessment or would have been if the former Member had made an application to that effect.