From memory I think human bio scaled down by 7 points for me in year 11.
Keep in mind though I did pretty badly my mark was around 68
So if you manage to do really well, the scaling will affect you less and you may even be scaled up if you’re on the right side of the curve.
It was a content heavy subject but it wasn’t too bad and since your taking 5 ATAR your experience should be a lot better than mine