How to control aggregation in Analytic Grid - Dashboard Designer

I have an analytic grid created in Dashboard Designer for SharePoint 2010 as shown below. The percentage values are shown in month wise and when they are rolled up to a year, they are summed up. I would like to have it averaged instead. I don't know where I can control it.

I figured it out. We have to change the AggregateFunction of the related Measure from "Sum" to "AverageOfChildren" in Analysis Service.