2. In order to determine which local municipalities whose territory is situated within the territory of the community must contribute to the sharing and to calculate the amount of each contribution, the community shall provide
(1) that only the municipalities whose tax base has increased are to be taken into account and that the amount of the contributions is calculated according to the growth in the tax base; or
(2) that all the municipalities are to be taken into account and that the amount of the contributions is calculated in part according to the tax base of the municipalities without regard to any change and in part according to the growth in the tax base.
The community shall not require more than one contribution per fiscal year from any municipality.