PP
Inracing has done a statistical series include what they call assessed odds which are provided by a third party. This is independent and on every runner as a prepost market. My assumption here is that they from the likes of AAP. I don't know, but this could be the closest that you will get to answer your query.
http://www.inracing.com.au/fckfiles/File/statistics/AOdds_Ranked.pdf