Understanding Plesk Watchdog statistics

[Robert Reinhard]

We have Plesk 8.3 installed. I've started using their Watchdog module to track server useage. Our server routinely has trouble with the amount of traffic we have and I think our MySQL queries need to be smarter. Anyway, looking at the stats from Watchdog, it seems like MySQL usage is low compared to so something else making up the "overall" usage. See the attached.

I was hoping someone with a lot of Plesk exeprience could help me understand what I'm seeing here. Can I not trust Watchdog's reports or am I missing something?