WASHINGTON — The number of unauthorized immigrants from India living in the U.S. in 2012 was about 450,000 — or approximately 4% of the total of 11.2 million unauthorized immigrants living in the country — according to report by the Washington, D.C.-based Pew Research Center.

The study said that the “most notable trend in the national origins of unauthorized immigrants over the past five years has been the continued decline in the number and share born in Mexico.”

As the number of unauthorized immigrants overall stabilized from 2009 to 2012, the number of the unauthorized from Mexico actually declined to 5,850,000 in 2012, down from 6.4 million in 2009 and a peak of 6.9 million in 2007.

India was the fourth-ranked country of origin for unauthorized immigrants in 2012. Ranked second was El Salvador with 675,000, followed by Guatemala with 525,000. Honduras ranked fifth with 350,000, followed by China (300,000) and the Philippines (200,000).

The number of undocumented immigrants in the U.S. hit its high point in 2007 at 12.2 million, when this group constituted 4% of the total U.S. population. Unauthorized immigrants currently make up 3.5% of the U.S. population of 316 million.

Unauthorized immigrants from India are the largest undocumented immigrant population in New Hampshire, the report said.

States where the unauthorized immigrant population increased in 2012 were: Florida, Idaho, Maryland, Nebraska, New Jersey, Pennsylvania and Virginia.

States where the population declined were: Alaska, Arizona, California, Colorado, Georgia, Illinois, Indiana, Kansas, Kentucky, Massachusetts, Nevada, New Mexico, New York and Oregon.

New Jersey had the largest gain of unauthorized immigrants between 2009 and 2012, jumping 75,000 to 525,000. Florida was second, rising 50,000 to 925,000, while Pennsylvania was third, rising 30,000 to 170,000.