merging two "100% stacked column" chart

[mahmoodn]

Hi
Assume I have the following table:

2
method1	method1	method2	method2
case a	case b	case a	case b
20	80	50	50

I want to draw a 100% stack chart however in the default chart in microsoft excel, one 100% stack chart is created for method1 and one is created for method2. How can I aggregate them in one chart?

please refer to the attachment which is what I want