"us gross sales will increase at the same rate as case volume. Which currently is 1.6%."
they did not give what the u.s. Case volume increase was. they didn't break that out. and there's no way to derive it from their numbers. your method assumes prices overseas after converting foreign currency to dollars was the same as u.s. Prices all year which is erroneous. that was my point, which obviously has eluded you.
arguably foreign case volume increased less compared to foreign gross sales increase, because the dollar has been plummeting, which would increase foreign sales converted to dollars. that's what's wrong with your method.