How to add up null values

Hello, I've created a chart based on the value in a particular field. The chart shows "null" in the legend, but doesn't display a bar for the "null" values. I would actually like to display this. Is it possible?

Many thanks

Dear @aliceoneill,
This really depends on the cofniguration, but by default, you should see the null values as well. Maybe there are just none that match the set parameters? Or perhaps they are filtered out by custom code?

For example, I have a very basic list:

All I do with it, is retrieve Number and Category, and Aggregate by Category:

Then, with this configuration, you can see the null values on the chart: