How many residents/patients should a CNA have on afternoons?

I've been working as a Certified Nurses Aide up until I finish Nursing school at a fairly small nursing facility. I've only been there for about 4 months, and I am very confused on why our care for the our residents is fairly poor. We are given 12-14 residents per aide, along with 2 showers per aide, and having to p out and pick up dinner trays (which I feel is a dietary aides job). I feel that is a lot of work to give proper and quality care. Its almost like a productions line,..gown people, pop them in bed, and do one bed check at the end of the night, cause thats all we have time for. Don't get me wrong, I don't mind working hard...but when its a 100 degrees outside and we have no air conditioning, its miserable. I was just wondering other peoples opinions on how many residents should an aide have per day?