Cumulative Bar Chart

[Steve]

I can't believe this does not exist in Cognos or maybe I am missing something.

In a Bar Chart, how do I display cumulative Bars?

Scenario:

I have a Date Dimension in a dimensional package which has Months as the 2nd level, Year being the 1st level. Months are Jan, Feb etc.. Objective is to make a cumulative Bar Chart for one year so the 1st bar would be for Jan, 2nd bar would be for Jan+Feb and so on.

I don't see any option to make that kind of a chart.   

Any ideas?

Thanks in advance
Steve