The average weight loss per week is 1 to 2 lbs of weight per week.
Losing anymore than 2 lbs of weight per week is not really healthy or safe so never try to lose more than 2 lbs per week otherwise your health may go downhill and you may become sick as a result.
Some people are able to safely lose 10 lbs per week but it's not recommended unless you're doing a diet that your doctor approves of.
2lbs of weight loss is the best way to go to stay healthy though.