The children of undocumented immigrants comprise a growing percentage of school children in the United States, according to a new Pew Research Center analysis of U.S. Census Bureau data.

The share of kindergarten though 12th grade students in public and private schools with at least one undocumented parent has increased from 3.2 percent in 1995 to 6.6 percent in 2009 to 7.3 percent in 2014, Pew reports.

As of 2014, there were about 3.9 million K-12 students with undocumented immigrant parents in the nation’s grade schools — up from 3.6 million in 2009.

According to Pew, some 81 percent (or 3.4 million) of the students with at least one undocumented parent were born in the U.S. and therefore citizens. Another 725,000 children of undocumented immigrants were undocumented themselves.

“Since the end of the Great Recession, the growth in the number of students with unauthorized immigrant parents has been entirely due to a broader increase in the number of children born in the U.S.,” Pew reports. “The number of students who are unauthorized immigrants themselves (and their share of the total) has declined.”

The states with the highest percentage of students with at least one undocumented parent are Nevada (17.6 percent), Texas (13.4 percent), California (12.3 percent), Arizona (12.2 percent), Colorado (10.2 percent), and New Mexico (10.1).

The Obama administration has placed a premium on protecting undocumented students from immigration enforcement, designating schools, bus stops and other education-related activities as “sensitive locations’ where immigration enforcement actions are generally to be avoided.

With the election of Donald Trump, some schools and school districts are vowing to ensure that undocumented students continue to be shielded from immigration enforcement on their campuses. Earlier this week the Los Angeles Unified School District said its schools would continue to be “safe zones” for undocumented students.