government divided into three branches: executive, judicial, and legislative. The executive and legislative branches operate primarily at the national level, although various ministries in the executive branch also carry out local functions. The judicial branch operates at both the national and local levels. Local governments are semi-autonomous, and contain executive and legislative bodies of their own. South Korea is a constitutional democracy. The constitution has been revised several times since its first promulgation in 1948 at independence. However, it has retained many broad characteristics and with the exception of the short-lived Second Republic of South Korea, the country has always had a presidential system with an independent chief executive. Under its current constitution the state is sometimes referred to as the Sixth Republic of South Korea. The first direct election was also held in 1948. Although South Korea experienced a series of military dictatorships from the 1960s until the 1980s, it has since developed into a successful liberal democracy. Today, the CIA World Factbook describes South Korea's democracy as a "fully functioning modern democracy". South Korea is ranked 45th on the Corruption Perceptions Index (9th in the Asia-Pacific region), with a score of 57 out of 100. Administrative divisions The major administrative divisions in South Korea are eight provinces, one special self-governing province, six metropolitan cities (self-governing cities that are not part of any province), one special city and one special self-governing city. Demographics In April 2016, South Korea's population was estimated to be around 50.8 million by National Statistical Office, with continuing decline of working age population and total fertility rate. In a further indication of South Korea's dramatic decline in fertility, in 2020 the country recorded more deaths than births, resulting in a population decline for the first time since modern records began. In 2021, the fertility rate stood at just 0.81 children per woman. The country is noted for its population density, which was an estimated 505 per square kilometer in 2015, more than 10 times the global average. Aside from micro-states and city-states, South Korea is the world's third most densely-populated country. In practice the population density in much of South Korea is higher than the national one, as most of the country's land is uninhabitable due to being used for other purposes such as farming. Most South Koreans live in urban areas, because of rapid migration from the countryside during the country's quick economic expansion