 In common with many other developed countries , Australia is experiencing a demographic shift towards an older population , with more retirees and fewer people of working age . In 2004 , the average age of the civilian population was 38 @.@ 8 years . A large number of Australians ( 759 @,@ 849 for the period 2002 – 03 ; 1 million or 5 % of the total population in 2005 ) live outside their home country . 
