Cant map DirectInput to Axis correctly

Hey,
i have a question regarding the RawInput plugin.
I am trying to get input from an ancient Microsoft SideWinder Force Feedback Wheel USB. And map the steering axis to the GenericUSBController Axis 1.
My problem is the values don’t directly go from -1 to 1 but when steering left to the center they go from 0 when steering all the way left to -1 just before the center. then it makes a jump to +1 and going down to 0 all the way to the right.

Is there a way to map this linearly to the GenericUSBController Axis?