Updated

Arrests of people trying to cross the U.S. borders illegally have plunged 61 percent in the last five years, according to the Department of Homeland Security.

Border patrol agents made nearly 1.2 million arrests along U.S. borders in 2005; in 2010, they made 463,000 arrests, the lowest level since 1972, shows federal data released Thursday.

The arrests cover all the U.S. borders – Southwest, Northern and coastal . The vast majority of the arrests, 97 percent,  occurred on the Southwest border in 2010, continuing the pattern of previous years.

The Homeland Security report speculated that the drop in the number of arrests over the five year period stemmed from U.S. economic conditions – which have weakened the pull of the jobs magnet – as well as stricter border enforcement.  The number of agents patrolling the border has more than doubled over the last six years.

Proponents of tighter immigration enforcement cast doubt on the data, and said that illegal border crossings remain a critical problem.

Dan Stein, executive director of the Federation for American Immigration Reform, or FAIR, which favors strict immigration policies, says lower rates of arrests don’t necessarily  mean that illegal immigration is decreasing.

“There is the economic reality of the change in [U.S.] economic conditions,” Stein said, “No one can be blind to the fact that there’s a depression going on, the unemployment rate is extremely high and congestion is high that [low-skill job] market.”

“But historically,” Stein added, “there always has been skepticism about what apprehension data means, per se.“

“There are many ways it can be lowered – through relaxed standards that make it easier to smuggle aliens through, or making it easier to get visas,” Stein said. “There are many ways that people can be entering either illegally or through fraud, rather than through crossing the border.”

Those who advocate for relaxed immigration policies said they welcome the arrest data, and said it should encourage political leaders to shift their focus to what to do about the estimated 11 million undocumented people already living in the United States.

“The data doesn’t change the fact that we have 11 million undocumented people among us,” said Maribel Hastings of America’s Voice. “Republicans keep saying we need to secure our borders before we even consider comprehensive immigration reform.  The border arrest data is another reason to deal  now with the situation we have inside our borders."

Ali Noorani, executive director of the National Immigration Forum, which advocates for a policy that will allow certain undocumented immigrants a pathway to legalization, said that bolstered border security obviously has worked.

“Numbers don’t lie,” he said, in response to those who doubt the data. “Apprehensions have gone down, all indicators point to that. To continue to waste taxpayer dollars without fixing our immigration system overall is outlandish."

The federal data showed that, as in the past, Mexicans accounted for the overwhelming  majority of border arrests. In 2010, they accounted for 87 percent of all border arrests, down from 92 percent in 2007, though up from 86 percent in 2005.

The peak year for border arrests is 1986, following the passage of the Immigration Reform and Control Act, or IRCA, which included provisions for bolstering border enforcement.

Follow Elizabeth Llorente on Twitter: @LlorenteLatino

Elizabeth.Llorente@FoxNewsLatino.com

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