I made a quick visual showing how many floors will still be built.
I find it's convenient to split the building into 5-floor groups where there is a new setback.
Current construction has completed the yellow, green and red setbacks and only has one more floor until the the purple setback is done. After that there is still one more 5-floor group to construct (teal), plus the top of the "sail" on the west side of the building.
By my estimation there is roughly about 6 floors to go, plus the decorative sail. Exciting!