There are a whole lot of things that would change zombie demographics. A major factor would be whether the zombies would be reanimated cadavers from cemeteries, of victims of the zombie plague disease.
That is, in a large part of the US west of the Mississippi, there are far fewer buried cadavers than in some place like New Orleans.
Whereas, if they were plague zombies, about the only thing that would matter is population density where you live.
Geography and seasons are also very important. Zombies frozen stiff or dehydrated into over-dried brittle beef jerky are going to be a lot less functional than in moderate and somewhat humid circumstances.
Personally, I like the idea of a mountain fortress with the mountain covered in black basalt, that in summer can give off 180F heat easily.
If zombies are made of dead meat, does that mean they can catch maggots? Would the maggots then also be zombies?
Or when/if their welfare and WIC checks get cut off or inflated out of existance.
If reanimated cadavers (remains) fall into the mix, there are a few thousand year’s worth which are mostly unmarked...