Some schools are two years behind. I was pretty shocked by the increase in tuition over a year but then realized the tuition was actually 2 years old in the NPC. Since some schools don’t even set the tuition for the coming year until the summer, the NPC isn’t going to be accurate. The first year my daughter’s bill was available July 7 and due Aug 11. Until July 7, I had no idea what I’d be expected to pay. The tuition went up about $2k per year, but we never got a lot of warning.
I think most change their NPCs as soon as they have the information for that year settled, so some time in the fall.