Vienna is the national capital, largest city, and one of nine states of Austria. Vienna is Austria's most populous city, with about 1.9 million inhabitants (2.6 million within the metropolitan area, nearly one third of the country's population), and its cultural, economic, and political center. It is the 6th-largest city by population within city limits in the European Union.
Vienna is known for its high quality of life. In a 2005 study of 127 world cities, the Economist Intelligence Unit ranked the city first (in a tie with Vancouver and San Francisco) for the world's most livable cities. Between 2011 and 2015, Vienna was ranked second, behind Melbourne. In 2018, it replaced Melbourne as the number one spot and continued as the first in 2019. For ten consecutive years (2009–2019), the human-resource-consulting firm Mercer ranked Vienna first in its annual "Quality of Living" survey of hundreds of cities around the world. Monocle's 2015 "Quality of Life Survey" ranked Vienna second on a list of the top 25 cities in the world "to make a base within." The UN-Habitat classified Vienna as the most prosperous city in the world in 2012/2013. The city was ranked 1st globally for its culture of innovation in 2007 and 2008, and sixth globally (out of 256 cities) in the 2014 Innovation Cities Index, which analyzed 162 indicators in covering three areas: culture, infrastructure, and markets. Vienna regularly hosts urban planning conferences and is often used as a case study by urban planners. Between 2005 and 2010, Vienna was the world's number-one destination for international congresses and conventions. It attracts over 6.8 million tourists a year.