How to make chart include all categories even if empty?

[caitlin]

Hi folks -

I've created a report that consists mostly of charts depicting test scores based on subgroups. Each chart includes a category for that subgroup and a category for "everyone else". The fields I am drawing the charts from show a 1 if the person is in that subgroup, or a 0 if they are not. In some cases, there are no test scores available for the subgroup, so the chart only shows the "other category".

This is confusing to the reader -- is there any way to force the chart to always show both categories, even if one is empty?

Thanks!

--Caitlin