How to show Average First Response Time and Average Handling Time on a graph for Service Requests

Summary:

We have a detail report by service request that uses certain calculations to take into account the number of hours worked a day by CS. We have the following working on the detail report. But, I am trying to add KPI's for Average First Response Time and Average Handling Time of SR's on a graph per CS rep. I cannot get these working using the Facts under the Service Request Lifecycle subject area. I tried using "Total" and then dividing by the # of SR's. I tried using the "Average" facts as well. Can