For anyone interested, Ohio State University Vet School has a wonderful site where they discuss nutrition and present some charts and percentages for pet diets....I have NO idea how to do link things, but if you type in
Veterinary Medical Center | College of Veterinary Medicine, you will see a lot of valuable information....there are lots of topics running down the right hand side of the page, that provides a lot of clarity and explanation regarding pet foods and pet nutrition. (not a subsidiary of RC!!!)