ScaleTransform parts of a Geometry

Question

So I have a chart Geometry which I wish to scale.

However, The chart is scaled differently at certain y ranges.

Say this is my y-axis

100
90
80
70
//
1
0

I will need to scale the part between 70-100 differently from the part between 0-1 and the part between 1 and 70. Is there a way to form a TransformGroup with multiple scaletransforms which only apply to values in between certain y values?

Thanks.