The statistics get flushed to disk on certain events, like service restart.
It looks like in the Application Event Log that the services get restarted upon each DAT update... is that correct?
McShield service started.
Engine version : 5400.1158
DAT version : 6155.0000
Number of signatures in EXTRA.DAT : None
Names of threats that EXTRA.DAT can detect : None
Additionally, if you are concerned about whether the on-access scanner is working, you can always create an EICAR and copy it to the computer as a test. VirusScan should pick it up right away.
The Application event you refer to is the On-Access Scanner reinitializing; it will do that after DAT updates and on service start.
You would have to refer to the System log to see any service stops and starts.