The amount that is currently paid is $39.7 billion. That's for the last fiscal year. Again, the OAG estimated not the dollar value, but that there was an error rate there of 20%.
Evidence of meeting #97 for International Trade in the 44th Parliament, 1st session. (The original version is on Parliament’s site, as are the minutes.) The winning word was deloitte.
A recording is available from Parliament.