Library income expended for public library service which derives from rental of the library's meeting rooms, part of its facilities or real estate holdings may be counted as part of local financial effort, and a library which charges rental fees for books may count that income as part of its local financial effort only if it makes available to its patrons an equal or larger quantity of new, free, informational and recreational materials of a parallel nature to those in the rental collection, or which duplicate the rental collection.
22 Pa. Code § 131.56