How to Create a Percentage Row Based Off Values Only Found in Proceeding Row?

Hi,

   Version: BI 4.0 SP8.3

Database: SQL Server 2012

Please see example below. I am trying to create the Total Percentage by Segment row.

For example: In Analysis, I created the Total Activities by Segment row by simply putting in a calculation to add the values of each Segment column. Now, I want to create the Total Percentage by Segment row that will display the percentage based off the All Total Activities number (in this example it is 210). In other words, the total for Segment 1 is 60 (B5), the total for All Segments is 210 (E5). The Percentage Share of 60 to 210 is 29% (B6):

This is very easy to do in Excel, but how would I accomplish this in Analysis?

Thanks,

Michael