No permit for the use of property by or for a tax-exempt
institution shall be granted by the Board of Appeals unless the tax-exempt
property within the Village is equal in assessed valuation to 10%
or less of all property as shown on a current Village assessment roll,
nor shall any such use be granted if the grant of such use shall so
increase the quantum of tax-exempt property in the Village so that
it shall exceed the aforesaid limitations; provided, however, that
notwithstanding such limitations, a use permit for a tax-exempt institution
may be granted if the order of the Board of Appeals shall incorporate
a condition based upon a legally binding agreement between the institution
and the Village that the Village shall receive annual payments of
such sums of money as will, in the opinion of the Board of Trustees,
fully compensate the Village for the rendition of municipal services,
whether such services be governmental or proprietary or directly or
indirectly, benefiting said institution.