3. The sums referred to in section 88.6 of the Act, shall be apportioned, for the Québec region, between the Réseau de transport de la Capitale and the Société de transport de Lévis in a proportion of 80% on the basis of the receipts generated from users of their respective public transit networks, and in a proportion of 20% on the basis of the contributions of motorists having their address in the territory of a municipality or of an Indian reserve located in their respective territories.