103.20. Notwithstanding section 100, a pension payable to a Member under subdivision 5.1 following an election made under section 103.18 after 31 December 1987 shall be adjusted annually, from 1 January 1989, at the time prescribed under section 119 of the Act respecting the Québec Pension Plan (chapter R-9) at the rate by which the rate of increase of the Pension Index determined under the said Act exceeds 3 %.