In order to be approved by the Borough as age-restricted residential development, every dwelling unit (except a unit for one manager) on a tract of land shall be permanently restricted by deed, by any lease and by notes on the recorded plan to the following occupancy limitations: a minimum of one head of household of each dwelling unit shall be age 55 years or older, or 62 years or older, or who is physically disabled as defined by Social Security disability regulations; and no person under age 18 shall live in the dwelling unit for more than 30 days in any calendar year. Any violation of such age restrictions shall be a violation of this Zoning Ordinance. In addition, in order to be approved as age-restricted development, the applicant shall establish an appropriate legal entity, such as a property-owner association that has the duty, authority and responsibility to enforce such age restrictions over time.