This is the best article I have read about Commonwealth vs Olympic medals. It's a South African site, but the message is the same for Australia - indeed all Commonwealth countries. The base message is for the Top 10 Commonwealth nations, If you win 6 Commonwealth medals, you can expect to win One Olympic Medal.
http://sportsscientists.com/2014/07/commonwealth-calibration/
http://sportsscientists.com/2014/07/commonwealth-calibration/