The Christian share of adults in the US has declined sharply since 2007, affecting nearly all major Christian traditions and denominations, and crossing age, race and region, according to an extensive survey by the Pew Research Centre. Seventy-one percent of American adults were Christian in 2014, the lowest estimate from any sizable survey to date, and a decline of 5million adults and 7percentage points since a similar Pew survey in 2007.The Christian share of the population has been declining for decades but the pace now rivals or even exceeds that of the country's most significant demographic trends, such as the growing Hispanic population.It is not confined to the coasts, the cities, the young or the other liberal and more secular groups in which one might expect it."The decline is taking place in every region of the country, including the Bible Belt," said Alan Cooperman, the director of religion research at the Pew Research Centre and the lead editor of the report. The decline has been propelled in part by generational change, as relatively non-Christian millennials reach adulthood and gradually replace the oldest and most Christian adults. But it is also because many former Christians, of all ages, have joined the rapidly growing ranks of the religiously unaffiliated or "nones": a broad category including atheists, agnostics and those who adhere to "nothing in particular".The report does not offer an explanation for the decline of the Christian population, but the low levels of Christian affiliation among the young, well educated and affluent are consistent with prevailing theories for the rise of the unaffiliated, such as the politicisation of religion, a broader disengagement from all traditional institutions and labels, the combination of delayed and interreligious marriage, and economic development.Overall, the religiously unaffiliated represent 23% of adults, up from 16% in 2007, Pew estimates. Nearly half of the growth was of atheists and agnostics, whose tallies nearly doubled to 7% of adults.The ranks of the unaffiliated have been bolstered by former Christians. Nearly a quarter of people who were raised as Christian have left the group, and former Christians now represent 19% of adults.Attrition was most substantial among mainline Protestants and Roman Catholics.The acute decline in the Catholic population is a new development. Most previous surveys have found that the Catholic share of the population has been fairly stable over the last few decades,Not all religions or Christian traditions have declined so markedly. The number of evangelical Protestants dipped only slightly as a share of the population, by 1 percentage point, and increased numerically.Judaism, Islam and Hinduism have generally held steady or increased their share of the population. Overall, non-Christian faiths represent 5.9% of the US population, up from 4.7% in 2007. ©2015 New York Times News Service..