15. Any person who has certain payable pension credits in excess of the fiscal limits established by the Income Tax Act (R.S.C. 1985, c. 1 (5th Suppl.)) is entitled to a supplementary benefit.
That supplementary benefit shall be established in respect of years of service credited after 31 December 1991, excluding the years referred to in subparagraphs a and b of the second paragraph of section 2, and it shall be equal to the amount by which the pension that would have been computed disregarding the benefit cap established under the Income Tax Act exceeds the pension payable according to those limits.