The historic wave of migration from Mexico to the United States, which over four decades brought 12 million immigrants to the country, has come to a standstill. That's what a new Pew Hispanic Center study released today found.

Using government figures from both Mexico and the United States, Pew found that from 2005 to 2010, 1.37 million people migrated from Mexico to the United States, but that was negated and probably overtaken by the 1.39 million people estimated to have migrated from the United States to Mexico.

Here's the graph that compares those numbers to the 1995 to 2000 numbers:

Pew gives this explanation for the immigration halt:

"The standstill appears to be the result of many factors, including the weakened U.S. job and housing construction markets, heightened border enforcement, a rise in deportations, the growing dangers associated with illegal border crossings, the long-term decline in Mexico's birth rates and changing economic conditions in Mexico."

Here are a couple of more highlights from the report:

-- "This sharp downward trend in net migration has led to the first significant decrease in at least two decades in the number of unauthorized Mexican immigrants living in the U.S.—to 6.1 million in 2011, down from a peak of nearly 7 million in 2007."

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