The main legislative body is the unicameral Legislative Yuan with 113 seats. Seventy-three are elected by popular vote from single-member constituencies; thirty-four are elected based on the proportion of nationwide votes received by participating political parties in a separate party list ballot; and six are elected from two three-member aboriginal constituencies. Members serve four-year terms. Originally the unicameral National Assembly, as a standing constitutional convention and electoral college, held some parliamentary functions, but the National Assembly was abolished in 2005 with the power of constitutional amendments handed over to the Legislative Yuan and all eligible voters of the Republic via referendums.