Amending Chapter 19-1300 of The Philadelphia Code, entitled "Real Estate Taxes," by providing that real estate taxes levied under that Chapter shall be based on the average of ten years of assessed values, to offset the affects of the BRT's Full Valuation Project and to allow real estate taxpayers who own existing properties to enjoy tax relief commensurate with that conferred upon those who enjoy tax abatements for new construction, and by making technical amendments, under certain terms and conditions. — Open Common Ground