Keep in mind that this traffic isn't always concurrent. For example:
Just because you have max IN at 9.5 and max OUT at 5, doesn't mean you've hit both at the same time.
From the bandwidth calculator, you're pulling just over 10 (10.84 to be precise) in the image there, so it's possible that you're duplexed, or it's also possible that this is just a glitch in your graphing software, depending on how often it's updated, the last is most likely . Most (like mrtg, etc) update every 10-15 minutes and will keep a bit of data stored.
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