8. In the case of injury to or mutilation of symmetrical organs the percentage of permanent impairment attributed to the least severe impairment is multiplied by an enhancement factor of one-fifth, and the percentage thus obtained is added to the percentage attributed to such impairment, unless otherwise provided for in Schedule A.
The enhancement factor shall also apply in the case of a pre-existing injury or mutilation.
R.R.Q., 1981, c. A-25, r. 6, s. 8.