Report for how many hours a job role performs

Hi- I am trying to create a report that shows how much each job role is utilized. I would like this report to display the planned hours each job role in our system has by month. I tried an hours and assignments report and am getting zeros.

When we set up a project, we use a template that contains job roles and then assign the roles to users. Is this what is impacting the reports and causing zeros? Thank you!