Yes, you can always pull these based on your report filters. If you have existing reports that no longer work, I imagine they're using fields that have been changed/deleted and cause your report to break. If you have manage access on the report(s), from the report go to Report Actions > Edit > then check out your filters.
You can use filters for when tasks/projects were completed (either actual or planned completion) and there's an option for 'past year' or 'last year' or you can set custom dates, alongside any other filters you want.