I'm having a problem with stacked column chart. Here is a working fiddle http://jsfiddle.net/jokullie/pvtvLfvy/ that demonstrates the problem.
What I want to do is, I want all objects with the same CHARTGROUP value to be stacked on top of each other and then all the different years should be grouped together on each month.
So, I want the first two records stacked on top of each other at month:1 or "jan", then I want records 9 and 10 to be stacked on top of each other also at month:1 or "jan".
The same should happen for all other months. I hope this makes sense, if not, please ask for clarification.