On 1 January 1901, the six colonies became a federation and the Commonwealth of Australia was formed. Since Federation, Australia has maintained a stable liberal democratic political system and is a Commonwealth realm. The population is 22 million, with approximately 60% concentrated in and around the mainland state capitals of Sydney, Melbourne, Brisbane, Perth and Adelaide. The nation's capital city is Canberra, in the Australian Capital Territory. Approximately 56 per cent of Australia's population live in either Victoria or New South Wales, and approximately 77 per cent live on the mainland's east coast.