How many Pomegranates to make 1 gallon of juice?

Pomegranates take a lot of work to prepare for juicing. I've been preparing some juice from the pomegranate bush I have in the backyard. Generally I prepare more than one at a time, but on the few occasions I've juiced just one, I got at most 2 oz. of juice and from smaller fruits about 1 1/4 oz. I recently prepared 12 pomegranates of varying sizes and got a yield of about 17 oz.

I would like to see how POM prepares it's juice, because for me it is very labor intensive.