Australia is made up of six states: New South Wales, Queensland, South Australia, Tasmania, Victoria, Western Australia; and two mainland territories: the Australian Capital Territory and the Northern Territory. In addition, Australia administers seven external territories, including the Australian Antarctic Territory and a number of islands in the Pacific, Indian and Southern Oceans. Australia is an independent Western democracy with a population of 20 million people. Government is based on a liberal democratic tradition, which upholds the right to freedom of speech and association, and a commitment to religious tolerance. Along with Canada, New Zealand and other former British colonies, Australia is a consitutional monarchy, recognising Queen Elizabeth II of Great Britain as head of state. Her representative in Australia is the Governor-General. The nation's political structure, as well as its legal and educational institutions, are based on British and American models. The Constitution gives the Federal Government power over defence, foreign affairs, trade and commerce, taxation, customs and excise duties, pensions, immigration and postal services. Other powers are held by the states.