NEW YORK

The Christian population in the U.S. has declined by nearly eight percentage points in the last seven years, according to new research released Tuesday.

The Pew Research Center said its survey of more than 35,000 Americans revealed 71 percent of adults described themselves as Christians, compared with 78 percent who came out in an equally proportionated survey conducted in 2007.

During the same period, the share of Americans who do not identify with any organized religion increased more than six points, from 16.1 to 22.8 percent.

"The drop in the Christian share of the population has been driven mainly by declines among mainline Protestants and Catholics," the survey concluded. 

The two divisions of Christianity shrunk by approximately three percentage points since 2007, it said.

The research also documented a racial and ethnic diversification among American Christians, with racial and ethnic minorities now making up 41 percent of Catholics, 24 percent of evangelical Protestants and 14 percent of mainline Protestants.

Despite the declining figures, the U.S. remains home to more Christians than any other country in the world and roughly seven-in-ten Americans continue to belong to some branch of the Christian faith.

The research said the share of Americans who identify with non-Christian faiths increased 1 percent, with growth especially great among Muslims and Hindus.

In another major survey last month, Pew Research said Islam is projected be the world's largest religion after 2070 if current demographic trends continue.

Between 2010 and 2050, Muslims are projected to increase by 73 percent while the number of Christians is projected to grow by 35 percent, at about the same rate as the global population, according to the research.