Inserting NaN in the module, the following graph is derived.
I prefer having 0 in my graph, because it's reflecting the true value.
But if you're still looking for a graph that bypasses 0, and connects only values, i think there's 2 choices:
1. Create a module that filters out zero, create a line chart out of the non zero values. Then at the bottom of the line chart, create a module with all values (including the zero), and use conditional formatting to highlight these zeroes, so that users can still tell when the zeroes happen.
2. The other option is to mathematically derive a value to replace the zero, so that we don't get what we see above in the NaN graph, eg if Jan = 1, Feb = 0, Mar = 5; then derive 3 for Feb so that there's a smooth line connecting Jan to Mar. However this approach has 2 problems, i.e. first of all, it sends the wrong message because i'm seeing Feb = 3 in the graph, but the module is saying 0. Secondly it's not easy to derive these values, especially when there could be more than 1 zero between values, eg Jan = 1, Feb = 0, Mar = 0, Apr = 0, May = 5.