Add an evaluation function. This needs to be a standard reportable function that can be attached to any/all activities. The survey is not a viable option as you have to create a separate survey for every activity and its too clunky to create. An LMS should have an evaluation function as standard.
There is a solution to this, create a survey in Microsoft Forms for each year. Then add an 'email trigger' to all events upon completion to direct your staff to that Microsoft Form to add to your evaluation. Microsoft even build a lovely excel report for you to collate all responses :)