Weekly religious service attendance. (Gallup)

With the exception of Utah, the top 12 most religious states in the nation are all in the South.

But Utah stands alone, according to the results of a Gallup survey of more than 175,000 Americans last year. That state sits atop the list and is the only one in the nation where more than half—51 percent—of those surveyed reported attending church every week. New England and the West dominated the bottom 10 states, with Vermonters reporting the lowest church attendance, of just 17 percent. In Washington, D.C., 23 percent of residents reported weekly attendance.

So, why is the South so dominant?

“The strong religious culture in the South reflects a variety of factors, including history, cultural norms and the fact that these states have high Protestant and black populations — both of which are above average in their self-reported religious service attendance,” according to Gallup. “Utah’s No. 1 position on the list is a direct result of that state’s 59% Mormon population, as Mormons have the highest religious service attendance of any major religious group in the U.S.”

Going to church, of course, is not the same as religiosity, but it serves as a decent proxy, Gallup argues: religion likely plays a more significant day-to-day role for someone who attends church weekly.

The results are based on how respondents answered the following question: “How often do you attend church, synagogue or mosque — at least once a week, almost every week, about once a month, seldom or never?” The margin of error for most states is plus or minus 3 percentage points, though it was as high as 6 points.