According to the GURU General Retention Schedule (formerly “Appendix 18”), course grade books should be retained for five (5) years – see the Student Records section for details on the policy.
If you used the Turnitin Grademark tool to assign grades for writing assignments, we strongly recommend you ensure that you maintain a local copy of the assignment grades. One option is to export the grade book from Turnitin as an Excel file. Alternatively, grades may also be copied into an Excel file or into an LMS such as Canvas or ANGEL.