The number of foreign-born residents from Latin American countries in Maricopa County has decreased by more than 8.5 percent, according to a new Census Bureau survey.

The bureau released its second American Community Survey five year estimate showing trends from 2010 to 2014. The previous ACS five year estimate spanned from 2005 to 2009.

Tom Rex with Arizona State University’s W.P. Carey School of Business said the primary factor for this drop was because of various legislation proposed or passed in Arizona that generally discouraged undocumented immigrants, primarily from Mexico and Latin America.

“The one in particular that had a big impact was the Employer Sanctions Law that was passed in 2008. It, in fact, did drive quite a large number of undocumented immigrants from the state,” Rex said.

Economic conditions in Mexico have also improved in recent years. Those changes led to a drop in immigration to the United States and more people returning to Mexico.