The maximum floor area ratio for any zoning lot shall not exceed 10.0. No floor area bonuses shall be permitted. However, for developments or enlargements on qualifying transit improvement sites, a floor area bonus for mass transit station improvements may be granted by the City Planning Commission pursuant to the provisions of Section 66-51 (Additional Floor Area for Mass Transit Station Improvements). For the purposes of this paragraph, defined terms additionally include those in Section 66-11 (Definitions).