Enterprise Performance Management (EPM) Workspace and storing Financial Reporting (FR) reports?

Our folder that contains all of the output from every Hyperion Reports Batch Scheduler process that has executed since out implementation (4 years) is on our server C:\oracle\Middleware\user_projects\epmsystem1\ReportingAnalysis\data\RM1\root" folder.

Do all of these folders and files need to be kept? Can they be deleted from the file share on the server or is there another process that needs to be followed. the server space being consumed is over 50GIG at this point.

We will never need to restore a report produced in the past? We can always execute again if we need to produce. the output is stored on other repositories.