The basis for the compulsory annual contribution due by local elected representatives in respect of the individual right to training, mentioned in articles L. 2123-12-1, L. 3123-10-1, L. 4135-10-1, L. 7125-12-1 and L. 7227-12-1, is determined on the basis of the gross annual amount of official allowances received by local elected representatives, including the various increases provided for in article L. 2123-22.