As a condition of subdivision or site plan approval, the municipal agency may require an applicant to pay his/her pro rata share of the cost of providing reasonable and necessary circulation improvements, and water, and drainage facilities, including land and easements, located off-tract of the property limits of the subdivision or development but necessitated or required by the development. "Necessary" improvements are those clearly, directly, and substantially related to the development in question. The municipal agency shall provide in its resolution of approval the basis of the required improvements. The proportionate or pro rata amount of the cost of such facilities within a related or common area shall be based on the following criteria.