WLS vets: help me understand the honeymoon
http://www.obesityhelp.com/morbidobesity/information/post+op +planner.php
Everybody is different, but this link can give you an estimate of what to expect as far as rate of weight loss. It does slow down the further out you get and is more difficult to maintain.
It is so important to get good habits in place from the start and keep it up. Long term success requires efort.