I'm at 38.2% lifetime, but I also think, the bigger and more your videos get exposed to a larger group, the harder it is to get people to watch whole videos.
It is real hit and miss, I have 2 videos that are very very similar, they were both trip videos, not motovlogs. One has 53% APV, one has 36%. They both have about the same number of views. So it can be a total crap shoot I think. I know AVD and APV both figure into how YT decides to put vids in search order, but I think like anything, you can really only look at some trends, if you have a video do well in any metric, do more of that.