Stacked Bar Charts

Hey guys,

It would be great if next time you guys work on the charting system you could add stacked bar charts. I have no idea what kind of code you guys use to make the charts, but since the basic concept of a stacked bar chart is just a bar chart with multiple layers, I'm hoping it's not a big task for you to do. Stacked bar charts are useful for comparing percentages across other variables like time. Also, I recently figured out how to use them to generate mazes in picture format.

Thanks!
Dave