How much water gets added to chicken?

Not long ago I unwrapped 1.5 pounds of raw chicken (breasts), diced it up, and then pan-fried it. Per usual, a lot of water came out during the cooking process, and I ended up cooking it until that excess water boiled away (but not so much that I dried out the individual pieces of chicken). When I weighed again, I was quite surprised to find that my 1.5 pounds of raw chicken had become just 1 pound of cooked chicken. Which leads me to wonder:

-how much water is added to chicken that is processed in a slaughterhouse for sale in grocery stores?

-Are there laws that limit the amount they can add ?

-If I slaughter a couple of chickens myself, gather 1.5 pounds of breast meat and fry it up, how much will it weigh after cooking?

They’ve cracked down a bit on this. Anyhow, it usually says on the packaging somewhere as to how much water is added, usually something like “up to 15% added chicken broth” or words of that nature.