Hi Gaspar

The Site logs report includes all of the interactions a user has with Totara and the type of interaction.

If you create a report with this source and include the course , username and time field as the columns (in that order)

You then can use the Aggregate setting in the columns to count username and group by year.

This will show how many times each course was accessed by users in each year.

You can filter the report by the event 'Course viewed' or any other event you wish to count.

regards