I have a beer question. How are Bud and Miller packed in your area, 24 or 30 pack cases?

I now live in central Arkansas and virtually all domestic beers are packed in cases of 30. I recently visited northern Arkansas and all the same beers were packed in 24 packs. I visit family north of Boston, and the beers are in 24 packs. When I make it up to Sebago Lake Region of Maine, the beers are in 30 packs.

Does anyone know why there is a difference from region to region? What do you have in your region?

Btw, a 30 pack here is usually about $23 after tax.