Rench that mark would get you a 99 aligned, pretty much for every year.
IMHO it is MUCH more difficult to get that sort of mark in the HSC:
all the trials/prev HSC (which have boosted your marks) you have done are based on q's that appeared in prev. HSC's.
There is always a q's worth or so of material in each HSC that would be unfamiliar and harder/a new type of q which requires a bit of luck to get the marks in (getting right setting out etc).
As an example; look at say the 2003 papers and a collection of 2003 trials, and after doing 20 2003 trials your marks in the 2003 trials may get inflated significantly, but the difference wouldn't be as large for the actual HSC exam.