NEW YORK: Fueled by immigration, America's Hindu population has reached 2.23 million, an increase of about one million or 85.8 percent since 2007, making Hinduism the fourth-largest faith, according to estimates based on wide-ranging study of religions in the nation.The proportion of Hindus in the US population rose from 0.4 percent in 2007 to 0.7 percent last year, according to the Pew Research Center's "Religious Landscape Study" published Tuesday.The study only gave the percentage shares of Hindus in the population, rather than numbers, but calculations by IANS using the population proportions in the report and census projections showed that the number of Hindus rose from 1.2 million in 2007 out of a total US population of 301.2 million that year to 2.23 million in 2014 in a population of 318.88 million. This amounts to an increase of 1.03 million or 85.8 percent in the Hindu population during the seven-year period.Pew said that it may have underestimated the size of the Hindu population.An earlier report from Pew on the future of world religions in April said that by 2050, Hindus would make up 1.2 percent of the US population and number 4.78 million. This would make the US Hindu population the fifth largest in the world.Looking at the socio-economic profile of Hindus, the new Pew report released Tuesday said they had the highest education and income levels of all religious groups in the US: 36 percent of the Hindus said their annual family income exceeded $100,000, compared with 19 percent of the overall population. And 77 percent of Hindus have a bachelor's degree compared to 27 percent of all adults and 48 percent of the Hindus have a post-graduate degree.Even as some American Christian organisations push for proselytisation in India, their share of the US population fell by 7.8 percent during the seven-year period, from 78.4 percent in 2007 to 70.6 percent last year, the Pew study said. That works out to about 11 million fewer Christians.However, "Christians remain by far the largest religious group in the United States, but the Christian share of the population has declined markedly," the report said.Underlying the change, there was a marked increase in the number of people who say they have "no particular religion," the study reported. About 23 percent of American adults fell into this category, up seven percent from the 16 percent in 2007. Included in this broad category are atheists who make up 3.1 percent of the total US population and agnostics, four percent.Compared to Christianity, the others are miniscule despite the increases. The second largest religion is Judaism, which accounts for 1.9 percent of the population, with an increase of 0.2 percent, the study found. It is followed by Islam with a 0.9 percent share of the population, up by 0.5 percent. Buddhism ties for the fourth place with Hinduism at 0.7 percent.The US census does not ask questions about religion. The Pew Research Center, an independent Washington-based organisation, surveyed more than 35,000 people across the US to fill this gap and arrive at the statistics.The rising trend of Hinduism in the US contrasts with that in India. The Pew report released in April said that the share of Hindus in the Indian population was expected to decline by 2.8 percent, from 79.5 percent in 2010 to 76.7 percent in 2050 even though their numbers were projected to grow to almost 1.3 billion by that year in a total Indian population of nearly 1.7 billion.