-1. I actually thought the instance reset back to 1 every week but then i realized that would truly suck. As some pointed out, why would you go back to beat levels you already completed?
Plus, sure there are people like me who only can get to play 1 or 2 hours with a full party a week. It's hard to match everyones schedules after all. Being reset, halved or set to 10 if above would make us lose the little time we got.