set in BP 337 (Local Government Code of 1983), a total of three cities became highly urbanized: General Santos (September 5, 1988), Lucena (July 1, 1991) and Mandaue (February 15, 1991). Lucena and Mandaue were special cases, in that because their re-classification into HUC status took place after the ratification of the Constitution (February 11, 1987) but before the effectivity of the Local Government Code of 1991 (January 1, 1992), their residents were allowed to continue to participate in the election of provincial officials as per their respective charters (as amended), by virtue of Sec. 452-c of the LGC. Residents of General Santos were already excluded from voting for provincial officials of South Cotabato since achieving cityhood in 1968; they were therefore unaffected by this exemption. 1992–present The Local Government Code of 1991 came into effect on January 1, 1992, and has remained in force ever since, though some amendments have been made. New requirements for creating cities, and upgrading cities to highly urbanized status, were instituted under this Act. The LGC of 1991 was also the first time the independent component city (ICC) category was introduced. These cities are those non-highly urbanized cities whose charters explicitly prohibited city residents to vote in provincial elections. They were finally made completely independent of the province from fiscal, administrative and legal standpoints. Upgrading Independent municipality to highly urbanized city The municipalities of Metro Manila, having been severed from the provinces of Bulacan and Rizal and made independent units in 1975, were converted to highly urbanized cities, beginning in 1994 with Mandaluyong. The most recent, Navotas, became an HUC in 2007. Only Pateros, which does not currently meet the population requirement of 200,000 inhabitants, remains the only independent municipality in Metro Manila. Component city to independent component city (CC - ICC) All that is needed is a congressional amendment to a component city's charter, prohibiting city residents to vote for provincial officials. There is a movement (Independent Calbayog City Movement) in Calbayog that pushes this and the draft bill is ready to be filed by the representative of the 1st District of Samar, Edgar Mary Sarmiento. Component/independent component city to highly urbanized city (CC/ICC - HUC) Since 1992, once a city reaches a population of 200,000 persons as certified by the Philippine Statistics Authority and an income of 50 million (based on 1991 constant prices) as certified by the city treasurer, the city