In the Admin Gear, I would use New Reports and utilize the Course Dashboard. You can export it as an Excel file. It will provide the Course Code, Course Name, Type, Number of Users Enrolled, Completed, In Progress and Not Started in the Material. You may need to format it a bit to get specific utilization rate you desire but it does provide the foundation information to complete the task. 

Adding on...the Courses - Users report will also give you that information if you run it open. It only includes course where users are enrolled. If you want a more extensive course inventory (including those that have no one enrolled) you can use the “export Course Data” option from the Course Management page.

Thank You!