When you set the Report Expiration Period, it applies to all Report Types. The firewall automatically deletes reports that exceed the period.
Configure Report Expiration Periods
Select Device > Setup > Management, edit the Logging and Reporting Settings, and select the Log Export and Reporting tab.
Enter the Report Expiration Period in days (range is 1-2000, default is no expiration). You can’t change the storage that the firewall allocates for saving reports: it is predefined at about 200 MB. When the firewall reaches the storage maximum, it automatically deletes older reports to create space even if you don’t set a Report Expiration Period.
Click OK and Commit.

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