Geraint is one of the Senior Engineers in the API Connect Analytics Squad. He has written a great article on how Rollover and Retention is handled in APIC V10.0.5.

https://community.ibm.com/community/user/integration/blogs/geraint-jones/2023/09/07/analytics-rollover-and-retention-in-v1005

https://higherlogicdownload.s3.amazonaws.com/IMWUC/UploadedImages/4oUE8DPARJi1VNvFpaMt_rollover-retention-L.png