Before you get redirected to an archive copy of Moodle (assuming there is not single-sign on) can a message pop up explaining that to access Previous years you need to log in to the relevant Moodle snapshot. If there's an OK, cancel button, then cancelling will take the person back to the current year.

You will now be redirected to the Moodle snapshot for [insert relevant option from below here]. Log in with your usual username and password and you will be automatically redirected to My feedback.

[options for each year]
2014/15
2015/16
the current year

[Continue] [Cancel]