Do not re-use a 360 Project by modifying the Start Date and adding new Subjects. It will limit your choices, may make previous data from the Project meaningless, and may trigger other unwanted results.

It is easy to start a new Project, importing the Layout, Questionnaire, and Scales from the old Project, and copying the Auto Emails.

If you want comparative data covering everyone, use the Group Report.

Or combine two or more data Export files (also on the REPORTS tab) in your spreadsheet or database program, allowing you to compare all data as if it were in the same Project.