I consider it half way drafted.
Chapter 1: A full draft, about half way revised, with a pretty clear idea of what the argument will be.
Chapter 2: What was a full draft is now being chopped up and a third of it is being farmed out to chapter 3. Not sure what is cohering this chapter. When I figure that out, it will probably need additional material worked in.
Chapter 3: The current chapter. It has a running start from the aforementioned excerpt from chapter 2, plus about 2500 words I wrote last week. Not sure what the argument is, and still struggling with the scope of what is going in it.
Chapter 4: Only the foggiest idea. Have not started it, and have not even really processed the sources I think are going into it.
Chapter 5: A 35-page draft, but a lot of it needs to be edited out, and some of the most crucial stuff isn’t even down on paper yet. This is really the key piece of the whole dissertation, and I have a fantasy of how it works out, but it needs a lot of work (as in additional, new writing) and revision to get there.