According to your description, you would like to show the value “YES” and “No” for the legend although the value of the field may has no “No” or “YES” ,right?
When a field is placed in the Values area of the chart, a legend item is automatically generated that contains the name of this field. So, if the field doesn’t have “YES” or “No”, the legend won’t show both “YES” and “NO” in the chart.
An available way that you can insert the “YES” to the table and set the values of other columns “0” if the table doesn’t have the record “YES”.


Best Regards,
Pirlo Zhang