My prediction is based on the fact that I only have 1 post from the past week, so I'll only have a single substantial return from Ecency points, and that came in tonight. Meanwhile, my average delegation will be going up, so as a result the APY drops. It'll take time for me to accumulate enough Ecency points to properly Boost more than once per week, but it'll happen!
You can see my Ecency point tally on the right-hand side of the results. Just prior to making this post, I had ~321 Ecency points, and I (successfully) spent 250 on a Boost for this post, so I'll have to replenish them with activity again.