DEPENDS, some quilts are a snap (cutting & piecing) other have a zillion pieces to cut, which means zillions to piece.
Sometimes I am in the mood to do hand work, or maybe let it go for months.
Quilting is a hobby, I work on it at my pace, mood and desire. It is not a race (except when we realize we need to finish asap for that special occasions). Some quilts inspire me to finish because it is beautiful and I am enjoying the process others (unfortunately) might become a UFO.
So it is hard to put a percentage up.... but I can say I'm ALWAYS drooling!