<P> Plurality religion by state, 2001 . Data is unavailable for Alaska and Hawaii . </P> <P> The United States government does not collect religious data in its census . The survey below, the American Religious Identification Survey (ARIS) 2008, was a random digit - dialed telephone survey of 54,461 American residential households in the contiguous United States . The 1990 sample size was 113,723; 2001 sample size was 50,281 . </P> <P> Adult respondents were asked the open - ended question, "What is your religion, if any?". Interviewers did not prompt or offer a suggested list of potential answers . The religion of the spouse or partner was also asked . If the initial answer was "Protestant" or "Christian" further questions were asked to probe which particular denomination . About one - third of the sample was asked more detailed demographic questions . </P> <P> Religious Self - Identification of the U.S. Adult Population: 1990, 2001, 2008 Figures are not adjusted for refusals to reply; investigators suspect refusals are possibly more representative of "no religion" than any other group . </P>

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