I'm curious as to why golf balls that are boxed by the dozen have 4 different sleeves with different numbers? Usually it's numbers 1-4 or 5-8. Why don't they offer a full dozen with just one number on them? For instance I like playing number 7's. It would be nice if I could buy a dozen balls stamped with the number 7. Not to mention it is far more difficult to find the 5-8 number sequence as opposed to the 1-4.