Harvest Expectations?

What are some opinions on what a decent harvest might be in a
9'x6'X5' Room with three 400w Hps With a 400 cfm fan with a good vented duct system....Understand that different strains yield far more or far less....maybe a Middle of the road estimate....thanks much

Its also in a CO2 enriched environment... Outta all you grow buffs i thought i could get at least one decent answer!! Come one now.....

Thanks you all for the great info it gos without saying that it is very much aprieciated!

1 lb every 2 months.

Ive heard 1 gram per watt from seed if you dont have any problems and good nutes. Less from clone.

well that would be 1200 grams which is just a BIT more than thats almost 3 pounds so its closer to 3/4 p every two weeks