How do I stop zoho sheet from including #N/A values in charts?

How do I stop zoho sheet from including #N/A values in charts?

In software packages that are not web-based, charts will not plot cells which return the value #N/A.  Unfortunately, zoho sheet seems to plot #N/A values as if they are equivalent to zeros.  Could you please tell me how to set cells so that they result in no value being plotted when a chart is created?
 
Huge thanks,
 
Cam