election. A special election will not be held if the vacancy occurred less than a year before the next regularly scheduled election. In the tables below, special elections where a change of party occurs have its leftmost cell shaded. In case of deaths of appointed sectoral representatives from 1987 to 1998, the president may appoint a replacement, with the advise and consent of the Commission on Appointments. Malolos Congress The Malolos Constitution did not provide provisions for holding special elections to fill vacancies in the Malolos Congress. Philippine Legislature National Assembly (Commonwealth) National Assembly (Second Republic) The 1943 constitution did not provide provisions for holding special elections to fill vacancies in the National Assembly. Commonwealth Congress No special elections were called for the Commonwealth Congress, elected in 1941 and first met in 1945; the much-delayed elections of 1945 were held in 1946. Congress of the Philippines Batasang Pambansa While the 1973 constitution had the mechanism for calling special elections in case of vacancies in the Batasang Pambansa, and several vacancies indeed happened, no special elections were called. Statistics By reason The most common reason for the vacancies which were filled by special elections since 1907 is resignation (a total of 28 instances)—both from leaving office to assume another position (21), and for other reasons (7). Death of the incumbent representative is the second most common, accounting for more than two-fifths of instances. Other reasons for holding special elections were to fill new seats created upon the establishment of new provinces (4 instances), and to fill the seats vacated after: a winning candidate was disqualified post-election (2), a representative was expelled from the legislature (1), or a representative was "dropped from the rolls" over a criminal conviction (1). By legislative era Most of the special elections—33, or more than half of the 61 conducted as of 2017—were held before the Second World War (1907–1941). In the space of 27 years after the war and before Ferdinand Marcos disbanded Congress and assumed dictatorial powers in 1972, a total of 18 special elections were held. In contrast, since the restoration of Congress in 1987 only 12 special elections have been held in the space of 30 years. Senate In the tables below, special elections where a change of party occurs have its leftmost cell shaded. Philippine Legislature From 1917 to 1934, senators are elected via senatorial districts; a vacancy mid-term had been filled