I really wish I could give a great and specific answer, but I'm not a measurement addict. Eventually I just noticed I hit the next milestone. I don't really remember going from waist to hip, but I managed it. I guess it was easier than watching the pot to see when it boiled. I also wear my hair up a lot, so it just happens to grow without me noticing.
Growth rates and stall frequencies are big factors in hitting any milestone, especially when you are chronically watching for any signs of progress.
Due to my weak ability to give you the answer that you want, I just hope you hit your next milestone soon!