What is the best way to report highest usage for many users on many courses?

Summary: Best way to report highest usage for many users on many courses?

Content (please ensure you mask any confidential information): We have 5,500 courses that I need to report on for highest usage by username. We have 14,000 plus users. Any suggestions on best way to report highest usage for many users on many courses? Should I add a category to the 5,500 courses and then report somehow using that category?

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