Sum Parts of a Column

Summary:

We have a table with the %age of absence per absence name however on the pie chart, I need to sum the ones that are at the lower end of the spectrum.

Content (required):

How to I sum all the %ages that are below a certain percent whilst leaving the ones above the threshold intact.

Version (include the version you are using, if applicable):

21D/22A about to move across

Code Snippet (add any code snippets that support your topic, if applicable):