There are eleven types of elections in Taiwan which, since 2012, have been unified into general and local elections, each held every four years, typically in January and November respectively. There may also be by-elections. Electoral systems include first-past-the-post, proportional representation, single non-transferable voting, and a parallel mixture of the above. General elections are held to elect the president and vice president jointly, and the 113 members of the Legislative Yuan. Local elections are held to elect magistrates of counties, mayors of special municipalities, cities, townships and county-administered cities, chief administrators of indigenous districts and village chiefs. Legislative Yuan and local elections are regional; citizens vote based on their registered address. Elections are supervised by the Central Election Commission (CEC), an independent agency under the central government, with the municipality, county and city election commissions under its jurisdiction. The minimum voting age is twenty years. Voters must satisfy a four-month residency requirement before being allowed to cast a ballot. History Elections were held for the first time in Taiwan by the Japanese colonial government on 22 November 1935, electing half of the city and township councillors. The other half were appointed by the prefectural governors. Only men aged 25 and above and who had paid a tax of five yen or more a year were allowed to vote, which was only 28,000 out of the 4 million population. The elections were held again in 1939, but the 1943 election was cancelled due to the Second World War. After the surrender of Japan and the transfer of Taiwanese control to the Republic of China, elections were held at the local level as well as to elect representatives to the National Assembly and the Legislative Yuan. The government of the Republic of China, led by the Kuomintang, retreated to Taiwan Island in 1949 after losing the Chinese Civil War with the Chinese Communist Party. At that time, the Temporary Provisions Effective During the Period of Communist Rebellion was enforced and largely restricted civil and political rights including voting rights of the Taiwanese people. In the eight elections starting from the 1948 Republic of China presidential election in Nanking (later known as Nanjing) to the 1990 Taiwan presidential election, the President was indirectly elected by the National Assembly first elected in 1947 and which had never been reelected in its entirety since. Similarly, the Legislative Yuan also had not been reelected as a