Your battery percentage is going to be:

    100 / DesignCapacity * MaxCapacity

Or, in the way that makes way more sense to me:

    MaxCapacity / DesignCapacity * 100

Which, with your results, yields something to the effect of:

    98.68%

It's kind of (read: very) dirty looking, but you can get the same result with:

    echo $(ioreg -l -n AppleSmartBattery -r | grep MaxCapacity | awk '{print $3}') / $(ioreg -l -n AppleSmartBattery -r | grep DesignCapacity | awk '{print $3}') \* 100 | bc -l