And this set, well, I add up all my values, divide them by five and get six over five. And the same thing for this guy, negative one, negative one, negative two minus negative one plus zero, plus one plus two divided by five. Well, these guys cancel and I get zero. Now look, in this set all my numbers have the same magnitude as these guys. But in this set, these first two numbers have the same magnitude as these first two numbers, but different signs. And that's why my average is zero.