SEC. 12. Apportionment of regional representatives.— There shall be 160 regional representatives to the interim Batasang Pambansa apportioned among the thirteen regions of the nation in accordance with the number of their respective inhabitants and on the basis of a uniform and progressive ratio as follows:
Region I, .12 representatives, consisting of the following provinces: Abra; Benguet, including the City of Baguio; Ilocos Norte, including Laoag City; llocos Sur; La Union; Mt. Province; and Pangasinan, including the Cities of Dagupan and San Carlos;
Region II, 7 representatives, consisting of the following provinces: Batanes; Cagayan; Ifugao; Isabela; Kalinga-Apayao; Nueva Vizcaya; and Quirino;
Region III, 16 representatives, consisting of the follow ing provinces: Bataan; Bulacan; Nueva Ecija, including the Cities of Cabanatuan, Palawan and San Jose; Pam panga, including Angeles City; Tarlac; and Zambales, including Olongapo City;
Region IV, 19 representatives, which comprises Metro Manila as follows: Cities of Manila; Quezon; Caloocan; and Pasay; and the municipalities of Valenzuela, Malabon, Navotas, Makati, Parañaque, Las Pinas, Mandaluyong, San Juan, Pasig, Muntinglupa, Marikina, Pateros and Taguig;
Region IV-A, 20 representatives, consisting of the follow ing provinces: Batangas, including the Cities of Batangas and Lipa; Cavite, including the Cities of Cavite, Tagaytay and Trece Martires; Laguna, including San Pablo City; Marinduque; Occidental Mindoro; Oriental Mindoro; Pa lawan, including Puerto Princesa City; Quezon, including Lucena City; Rizal; and Romblon;
Region V, 12 representatives, consisting of the following provinces: Albay, including Legaspi City; Camarines Norte; Camarines Sur including the Cities of Iriga and Naga; Catauduanes; Masbate; and Sorsogon;
Region VI, 16 representatives, consisting of the follow ing provinces: Aldan; Antique; Capiz, including Roxas City; Iloilo, including Iloilo City;and Negros Occidental, including the Cities of Bacolod, Bago, Cadiz, La Carlota, San Carlos and Silay;
Region VII 13 representatives, consisting- of the fol lowing provinces: Bohol, incloding Tagbilaran City; Cebu, including the Cities of Cebu, Lapu-Lapu, Mandaue, Toledo and Danao; Negros Oriental, including the Cities of Bais, Camlaon and Dumaguete; and Siquijor;
Region VIII, 10 representatives, consisting of the followi ng provinces: Leyte, including the Cities of Ormoc and Tacloban; Southern Leyte, Eastern Samar; Northern Samar; and Samar, including Calbayog City;
Region IX, 8 representatives, consisting of the following provinces: Basilan; Sulu; Tawi-Tawi; Zamboanga del Norte, including the Cities of Dapitan and Dipolog; and Zamboanga del Sur, including the Cities of Pagadian and Zamboanga;
Region X, 9 representatives, consisting of the following provinces: Agusan del Norte, including Butuan City; Agusan del Sur; Bukidnon; Camiguin; Misamis Occidental, including the Cities of Oroquieta, Ozamis and Tangub; Misamis Oriental, including the Cities of Cagayan de Oro and Gingoog; and Surigao del Norte, including Surigao City;
Region XI, 10 representatives, consisting of the following provinces: Surigao del Sur; Davao del Norte; Davao Oriental; Davao del Sur, including Davao City; and South Cotabato, including General Santos City;
Region XII, 8 representatives, consisting of the following provinces: Lanao del Norte, including Iligan City; Lanao del Sur, including Marawi City; Maguindanao, including Cotabato City; North Cotabato; and Sultan Kudarat.
The foregoing apportionment shall not be considered a precedent in connection with the reapportionment of repre sentative districts for the regular National Assembly under Section 2, Article VIII and Section 6. Article XVII of the Constitution.
Notwithstanding the foregoing provisions, the number of regional representatives for any region shall not be less than the number of representative districts therein existing at the time of the ratification of the Constitution. There are also allotted two additional seats for regional representatives to Region IV in view of inhabitants, such as students, in the region not taken into account in the 1975 census.