Amending Chapter 19-1800 of The Philadelphia Code, entitled "School Tax Authorization," by providing that real estate taxes imposed by the Board of Education of the School District of Philadelphia on a property shall not increase in any one year by more than a specified percentage as the result of an increase in the assessed value of the property as returned by the Board of Revision of Taxes; by providing that if the growth in the total assessed value of all real estate in the City exceeds a specified percentage in any year, then the rate of the real estate tax imposed by the Board of Educatio — Open Common Ground