Yield is a determination of space, time, and lighting. There are general rules, like grams per watt, but on the whole there is no given yield for a person. Many variables come into play.
Some things you can do to maximize yield to time is to switch to an effective hydroponic system and to use a quality nutrient system. Coco has been more forgiving to me versus other methods. Advanced Nutrients, Canna Nutrients, and Humboldt Nutrients all provide very effective systems. Humboldt Nutrients and Advanced Nutrients are more complete systems. A good AN nutrient system would cost about $500 up front that could cover a good 20 plants worth of growing. The Humboldt Nutrients system is about $100 less and lasts about as long. There are many "extras" but you don't need them all.
There's a ton more to it than that though... And I am short on time.
Take a look. It's in a book. A reading rainbow.