I think you're counting "1" as you start the trick, but that's before you've done a full rotation, so that should be "0", and we'd call that a total of 19.
We'll count "0" at the point where the ken is horizontal, and in front of your left shoulder (as seen in this video) for the first time. Up to that point we consider that you're still in the 'entry' to the trick.
Still, well done for setting a new record! :-)