Journal Archive Oldest/youngest item date NULL

Hi All,

I need to figure out which Journal archives can be deleted by looking at the oldest and youngest item in the archive. When I run the sql query to pull the oldestitemdateUTC and YoungestItemDateUTC it shows as NULL for most of the archives. Is there a way to set this? Using the expiry process isn't an option because we are looking at processing against 3+Billion items.

Running EV 10.0.4 HF3

Any suggestions/solutions are much appreciated!