What is the difference between 0 and N/A?
As this report is all based on proportions with the Activity Goal acting as the denominator, if there is no Goal set for a particular employee, that field is going to display a N/A. So, as you can see here, Jaclyn doesn't have a Internal Interview goal set: http://cl.ly/image/2a3V0w282o0v
A 0 on the other hand means that there is a goal set for that user but that they have not made any progress towards completing it!
In this case, Marie Curie has not logged any Stage 2s and hasn't made any progress towards completing her goal. However, we don't actually know how many Calls she has made because she doesn't have a goal set for Calls.
If you see N/A and want to correct for that, consult your InsightSquared administrator and go to Settings > Activity Goals.