My growth rate varies greatly depending on the time of the year, so the month at which I start growing from CBL/SL affects how long it takes me to get to the next milestone. If you've made note of changes in your growth rate depending on season, make sure you take that into consideration when projecting how long it should take you to reach your milestones.
In my case, my hair grows fastest from around March to August or so. So if I'm trying to reach a milestone and my starting point is in October, I'm going to be immediately hitting my slowest months, so I won't see progress as fast as if I had started in the spring.
But to actually answer the question
, seems like 6 months is about average, based on the replies--and also my personal experience.
In 2005 it took me 6 months to go from just past CBL to full APL. This was right after my BC and I was co-washing daily and wearing puffs and buns during this time period.
More recently, I started at around SL in January 2009 and was just starting to pass APL in July, so it was about the same time frame. I was washing, DC-ing, and straightening once a week during this period.
ETA: Miss_C I love your avatar!