A new survey has found that the United States will no longer be a majority Protestant nation in the future as long as declination of affiliation with many Protestant churches is sustained over the years.

According to a study conducted by the National Opinion Research Center at the University of Chicago, the portion of American population who said they were Protestant decreased from 63% to 52% while the number of Americans who identified themselves as being non-religious increased from 9% to 14%. Many non-religious subjects were former Protestants, according to the survey.

The study was based on three decades of religious identification questions in the General Social Survey, which the opinion center conducts to measure public trends.

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

In the survey, being Protestant was defined as being a member of a Protestant denomination, such as United Methodist Church or the Assemblies of God. Members of Church of Jesus Christ of Latter-day Saints and members of other independent Protestant churches were included in the category.

Smith indicated the reason for such decline by pointing to a problem which has been pervasive across many mainline Christian denominations - large crowd of young adolescents and adults has been leaving churches now possibly identify themselves as simply being “Christian,” a choice on the survey.

The Roman Catholic population however has remained relatively stable with a population share of 25%.

People belonging to other faiths, including Islam, Orthodox Christianity or Eastern believers increased from 3% to 7% between 1993 and 2002.