Total All Attributes for Model Type

Using Ember Light Table, I generated a table with yearly batting statistics for a play. At the bottom of the table I'd like to have totals for every column. What's the best way to go about summing every attribute to get career totals?

I can't figure out whether I should manually create computed sums for each attribute (doing so would suck) or if there's a simpler way. Thanks for any help!