I'm not sure if you wanted to average over the complete width of the plot... and just have a number pop up on the screen representing that average, in which case eTech's answer is good. If you want a line passing through the middle of your inductor waveform that represents the average, then the attached will do this. What I did was set up a behavioural voltage source that outputs a voltage equal to the instantaneous current. I then filtered it to give the average. However, this output is a voltage and not a current, so I set up a behavioural current source to output a replica of the voltage, so you get a current. This makes it much easier to fine tune the filter components to increase/decrease the averaging etc. I am sure there are simpler ways of replicating the current directly, but filtering voltage is much easier than filtering current
If you want to zoom in to a precise part of the waveform, right click over the Time axis and set your interval as needed. This works for mine and eTech's answers above.
Have a play with the attached. If you celebrate Christmas where you are, have a good one