Count of the attributes at lowest granularity

Hi All,

I am trying to calculate the average of the measure wrt to a dimension. I am implementing the Measure/Count. of the attribute. This attribute has the lowest granularity in the dimension.

In the Calculations Tab I am creating a measure like Count ([Dim Department] .[Calls])

Lets suppose I have 4 departments with diff number of calls targets like this. 

when I use the above expression the result I am getting is same for all departments as shown below. 

Am I missing any thing is the expression or do I have to use any other expression to get a count.

Can someone please look into this.

Thanks,

VSP