Agreed. Even Dawkins admits that he can only really say “God probably doesn’t exist.”
I got the list from The God Delusion. Dawkins says that while there are many people who would place themselves in the first category (I know god exists), he doubts that there are many people who would say they are a 7 (I know god doesn’t exist). He included it only for symmetry. He says he is a 6 leaning to 7.