It is the policy of this State that low-income housing projects developed under Section 515 of the federal Housing Act or that qualify for the low-income housing tax credit under Section 42 of the Internal Revenue Code shall be valued at 33 and one-third percent of the fair market value of their economic productivity to the owners of the projects to help insure that their valuation for property taxation does not result in taxes so high that rent levels must be raised to cover this project expense, which can cause excess vacancies, project loan defaults, and eventual loss of rental housing facilities for those most in need of them, low-income families and the elderly. It is the intent of this State that the valuation required by this Division is the closest representation of cash value required by law and is the method established as proper and fair.