Though the number of illegal immigrants living in the United States has dropped by 1 million [between January 2008 and January 2009], the number of undocumented Indians has increased by 64 percent, data released by the Department of Homeland Security showed.

India ranks third in terms of percentage increase of the undocumented from 2000 to 2009, Honduras, with an increase of 95 percent, and Guatemala, with 65 percent, rank top in the same period. Mexico's share was 42 percent.

The estimates are based on admission dates and length of visit by class of admission and not actual population counts. Length of visit, which is calculated by matching arrival and departure records, is subject to more error than admissions data, the DHS cautions.

Currently, 200,000 Indians live in the United States without proper documents. That is only 2 percent of the total illegal population of 10.8 million.

Indians rank sixth in the illegal population list. Mexico tops this category with 6.7 million or 62 percent, followed by El Salvador (530,000), Guatemala (480,000), Honduras (320,000) and the Philippines (270,000). South Korea too has 200,000 undocumented people in the United States, but the rate of their increase is only 14 percent.

India's case is significant for other details too. Data shows that in 2000, 120,000 undocumented Indians were living in the United States. It was 1 percent of the total undocumented.

In 2005, that number increased to 280,000, a record. In the next three years, it continued to decrease. In 2006, it decreased to 210,000; in 2007, it became 220,000; and in 2008, it was only 160,000. But 2009 saw an increase of 40,000 people.

The DHS said that between January 2008 and January 2009, the number of unauthorized immigrants living in the United States decreased 7 percent from 11.6 million to 10.8 million.

In 2000, it was only 8.5 million and grew to 11.8 million between 2000 and 2007, DHS said.

"Of the 10.8 million unauthorized immigrants in 2009, 4 million (37 percent) had entered the United States after January 1, 2000. An estimated 0.9 million (8 percent) came to the United States between 2005 and 2008, while 30 million (28 percent) came during 2000 to 2004. Forty-four percent came to live in the United States during the 1990s, and 19 percent entered during the 1980s."

"The overall annual average increase in the unauthorized population during the 2000-2009 period was 250,000." The financial crisis is termed as the main reason for the decline in the number of undocumented. Tougher border enforcement and a national crackdown on illegal immigrants too helped this process.

Some researchers conclude the drop is not because fewer illegal immigrants are coming in, but because more are leaving. "The illegal population is falling significantly. The only way for that to happen is for a lot more people to be going home. The decline in the population begins before the economy turns down. That suggests that, at least initially, it is because of the stepped-up enforcement that increased during the end of the Bush Administration," said Steve Camarota of the Center for Immigration Studies, which advocates reducing immigration.

Other analysts disagree, saying slower migration flows are a worldwide trend associated with the down economy. "It is really driven by fewer people coming in," said Jeanne Batalova, a researcher and policy analyst with the Migration Policy Institute based in Washington, DC.