Chapter 1 What’s New for FortiOS 5.2.1 : New features in FortiOS 5.2 Patch 1 : Include bandwidth and setup rate statistics in the event log
  
Include bandwidth and setup rate statistics in the event log
Bandwidth and setup rate statistics are vital for customer’s units health reports.
The advantage of these parameters are:
Improves performance on FAZ. Simple query small logs makes FAZ build reports faster and have more idle time for other reports.
Reduces amount of logs send to FAZ.
Uses less disk space on FAZ for the same report type.