Hi Jac,
Have you tried GraphBuilder? If not, here is a quick overview of how to format the data and place the variable in GB:
First the table:

Note that to have the correct order in the sequence of months, you may need to go to Column Properties > Value Ordering
Here is the GB using this table:
- Drag the Month column to the X-axis area
- Drag Data 1 to the Y-Axis area
- Drag Data 2 to the top of the Y-Axis area
Thierry R. Sornasse