I. The amount of the annual grant to any school district duly organized, any city maintaining a school department within its corporate organization, any cooperative school district as defined in N.H. Rev. Stat. § 195:1, or any receiving district operating an area school as defined in N.H. Rev. Stat. § 195-A:1, shall be determined as follows:
(a) Determine each municipality’s equalized valuation per pupil by dividing the municipality’s equalized valuation by the average daily membership in residence within each municipality. Assign each municipality a rank beginning with the municipality having the lowest equalized valuation per pupil ranked as number one, and continuing therefrom.
(b) Determine each municipality’s median family income, and assign each municipality a rank beginning with the municipality having the lowest median family income ranked as number one and continuing therefrom.
(c) Add the rankings assigned in subparagraphs I(a) and I(b) and divide the sum by 2 to yield the building aid factor.
II. (a) The amount of the annual grant in this subdivision shall be a sum equal to a percentage of the amount of the annual payment of principal on all outstanding borrowings of the school district, city, cooperative school district, joint maintenance agreement, or receiving district, for all approved costs of construction or purchase of school buildings and school administrative unit facilities, for grants approved on or before July 1, 2013 according to the following table:

	Building Aid Factor	Single District	Preexisting District in a Cooperative School District, Area School, or Joint Maintenance Agreement
	0-59	60 percent	60 percent
	60-69	55 percent	60 percent
	70-89	45 percent	55 percent
	90-114	40 percent	50 percent
	115 or greater	30 percent	40 percent

(b) For projects approved after July 1, 2013, the amount of the grant to any school district, city, cooperative school district, joint maintenance agreement, or receiving district shall be a sum equal to the percentage of all approved costs for construction or purchase of school buildings according to the following table:

	Building Aid Factor	Building Aid Grant
	0-59	60 percent
	60-69	55 percent
	70-89	45 percent
	90-114	40 percent
	115 or greater	30 percent

III. A cooperative school district, receiving district operating an area school, or joint maintenance agreement grant amount shall be determined by calculating the percentage of the average daily membership in residence represented by each municipality which has entered into the agreement and multiplying this percentage by each municipality’s percentage of annual building aid eligibility under paragraph II of this section. This product shall be multiplied by the projected cost of the building project. The sum of the resulting products shall be the annual building aid grant for the cooperative school district, area school, or joint maintenance agreement.