I have a learning list for 12,000+ employees and I need to determine the
average number of courses per employee / per department. Is there a formula
we can use?

Employee Department Head Course
John Doe Steve Buck Learning 101
John Doe Steve Buck Learning 102
John Doe Steve Buck Learning 103
John Doe Steve Buck Learning 104
Robert Smith Steve Buck Learning 501
Charlene R. Matt Mick Learning 101