current sensor on arduino inaccurate at zero Load
I think you are looking at the quantization noise of the Analog to Digital converter. You can check this by checking what values the ADC spits out with a simple analogRead(pin); and I bet you'll see only that value change a couple counts up or down. This means that you are working at (or very close to) the best possible resolution for the current setup. You should probably just disregard the lowest digit.

You can improve your readings by changing the full scale range of the current clamp by increasing the 33 ohm burden resistor and change the parameters in the software accordingly, but that reduces the maximum current you can measure.