According to a new study, the number of Americans who identify themselves as Protestants dropped by 11 percent in the past 10 years, while the number of people who said they had no religion rose from 9% to 14%.

The study, conducted by the National Opinion Research Center at the University of Chicago, was based on three decades of religious identification questions in the General Social Survey.

The United States "has been seen as white and Protestant," said Tom Smith, director of the General Social Survey to the Associated Press. "We're not going to be majority Protestant any longer."

The AP added that “The United States will no longer be a majority Protestant nation in years to come, due to a precipitous decline in affiliation with many Protestant churches.”

Respondents were seen as Protestant if they were members of any Protestant denomination, including the United Methodist Church or the Assemblies of God; even Mormons were placed under the “Protestant” Category.

The survey found that in general, many youth and adults left the churches in large numbers, while a larger non-Protestant immigrant population increased. Additionally, Smith explained that some former Protestants might be identifying themselves as merely “Christian” in the survey.

In other religious categories, Roman Catholic congregants remained relatively stable as a quarter of the U.S. Population, while people who say they belong to Islam, Orthodox Christianity or Easter faiths increased from 3% to 7%.