(c) Housing does not fail to meet the requirements for housing for elderly persons by reason of persons residing in the housing as of August 1, 1989, who do not meet the age requirements of paragraph (b), clauses (2) and (3), if new occupants of the housing meet the age requirements of paragraph (b), clause (2) or (3). In addition, housing does not fail to meet the requirements by reason of unoccupied units if unoccupied units are reserved for occupancy by persons who meet the age requirements of paragraph (b), clause (2) or (3). § Subd. 3. Age.