Good info anthonychea.
In connection to your post, maybe you or we can compare what BHP and RIO and FMG claim to have on their performances (or books) as well.
I know such involves a lot of work and research, but whoever got the info or time to do it, just champion it guys, so we can have that info to look at.
Cheers anthony, keep up the good effort mate.
Regards,
RVINTL.