Well, if you manage your time right and bill for all time spent instructing. Far to many CFI's give far to much of there time away. In a busy flight school in a location with good weather conditions for flight training, you should be able to do at least 24,000 per year depending on what you get per hour for flight, pre and post briefing and for teaching ground school. As for flying time 800 to 1000 hours in a year is not unreasonable, some places may be a bit less that than that. With the ecomomy slowing down the demand for flight training may fall off a bit too. That is something to look at too.