A global average of 17c doesn't even mean it's necessarily 17c anywhere in the world. That's not how averages work. It could be 0c in half the world, and 34c in half the world, and the global average would be 17c (and yet it would be 17c nowhere).
The point of global averages is to identify trends, which are not isolated to a particular region.
Indeed, it is from a year ago. And it was posted 10 months ago, and every other comment in this thread is from 10 months ago.
Did you think this was just posted? What point are you trying to make?