Nope, it's state-by-state. Thankfully, only SOME of the states have a ridiculously high AoC. Vt. is 16, Mass. is 16, N.Y. is 17, N.J. is 16, Calif. is 18. I don't know any others off hand, but IIRC it's something like 27 or 28 states that are 16, and only 10 or 12 that are 18, with the rest being 17.