Many people talk as if you "get" your 2016 UY pts (for a Feb UY) on Feb 1, 2016. This presentation makes it easier to see that they are available well before that.
So your 2016 UY pts were "allocated" on Feb 1, 2013...and the chart shows the dates that you moved them into your 2015 and 2017 UYs.
Hopefully, this means fewer questions about "do I have to wait until Feb 1, 201x to book a stay with 201x UY pts?" Now it's clearer that those pts are allocated well in advance.