How to measure ground turkey

I bought a package of Perdue ground turkey. The entire package is 16 oz. Nutritional label says there are 4 servings, 4 oz. each. So I put some spray oil in the frying pan, cooked the turkey and decided to weight the whole thing. It only weighs 11 oz. So I lost 5 oz while cooking it. So in my opinion, the label is misleading. My serving size is only 2.75 oz when cooked, not 4 oz.

So when I'm adding ground turkey to my diary, should I add 4 oz even though in reality it's only 2.75 oz?