5. The gross income of a victim who, at the time of the accident, does not hold employment corresponding to employment determined for him by the Société but who, in the 5 years preceding the date of the accident, has held such employment, is calculated by taking the highest gross income earned by the victim from such employment, computed according to section 1 or 2, as the case may be, indexed according to the method indicated in Schedule II and readjusted using the total of the adjustment factors provided for in Schedule I.