Step Consistency

I've got my Carving CNC CNC6040+G540+Ethernet SmoothStepper+Mach3 set up, and while I wait for my spindle I'm doing some measurements.

My calibration is 400 steps per mm.

I use Jog mode with 0.01mm steps and get the following data on my dial test indicator:

(Y axis, my X axis is similar)
Reading, Step
0.010
0.021 0.011
0.025 0.004
0.039 0.014
0.045 0.006
0.056 0.011
0.067 0.011
0.073 0.006

Is that typical of what I should expect? Could I be tuning my stepper motors differently?

If I do four or five steps in one direction, then one step back, it looks as though there is about 0.008mm backlash -- is that typical?

Thanks,
Tom