13/15.
I do not like that they use some of the new nicknames instead of the tradiitonal ones. For instance, Arizona should be listed as “The Copper State”. Connecticut is not on the list, but it should be known as “The Nutmeg State” not “The Constitution State”.
Citizens of Texas are Texans, those from Nevada are Nevadans and those from Vermont are Vermonters. However, citizens of Connecticut are known as Nutmeggers and those from Massachusetts are Bay Staters.
I became interested in state nicknames when I crossed from New Hampshire into Maine. The sign at the border referred to Maine as "Vacationland." I thought at the time, "isn't Maine the Pine Tree State?" The new nickname must have been coined by Chamber of Commerce types.
Incidentally, I got into an argument with some New Mexicans when I referred to their state as the Cactus State, a recognized nickname for New Mexico, on an online forum. They angrily retorted that they live in the Land of Enchantment. But if I were a New Mexican (and I almost became one, as I once considered moving there), I would prefer to have my state named for a tough and resilient plant rather than for occultic black arts practices.