I'm trying to create a KPI widget that uses the "comparison indicator" feature, but I can't figure out how.  I suspect my problem is something to do with the table I've setup.

Column 1 is a Plain Text Column with Months of the Year, like January, February, March.

Column 2 is a Numberic Column with whole numbers, like 10, 20, 38.

I want a KPI widget that shows the latest value (38) for the latest month (March) with a little green arrow showing that the value is up from February's 20.

Obviously I am way off base with my table because I can't get past Step 2 in the KPI Widget Editor.  

Can someone point me toward any information that will help me set up the right kind of table or tables?  I can't figure out what the KPI editor means my "Group" (it doesn't find anything to group by), and I can't figure out how I would tell it to use the data table row on top as the current value and the next row down as the previous value.  For me, these options are always grayed out.

I have been looking everywhere for even basic documentation to help with the KPI Widget Editor and am finding nothing.