A little over 7 percent of U.S. students in kindergarten through 12th grade have at least one undocumented parent, according to Pew Research.

While the number of unauthorized immigrants in the U.S. has stayed stable since 2009, there are now 3.9 million students living in households of parents without legal status, an increase from 3.6 million in 2009.

Of these children, almost 6 percent were born in the U.S. and a little over 1 percent are undocumented themselves, though the number of students without legal status has been declining in recent years.

RELATED: Trump Adviser Kris Kobach Warns: No 'Free Pass' for Undocumented Immigrants

The fate of undocumented families living in the U.S. is once again in focus following Donald Trump's election. During his campaign the president-elect pledged to deport millions of undocumented immigrants. Trump recently said in an interview that the focus will be on those with criminal records, though a member of his transition team said that no undocumented immigrant will get a "free pass" and suggested some families may end self-deporting "as jobs and benefits dry up."

Nevada has the highest percentage of students with at least one undocumented parent; these children make up 17.6 percent of the schools' population, though the number of immigrants without legal status in the state fell by 30,000 since 2009.

RELATED: 'Lives in Limbo': Undocumented Youth's Limited Opportunities

Texas has the second highest rate (13.4 percent) and California is third (12.2 percent.)

The numbers have fluctuated over the last decades. In 1995 about 3.2 percent of the U.S. student population had one unauthorized parent; it rose to 7.2 percent in 2007. The Great Recession may have caused a sharp decline; the number fell to about 6.5 percent in 2008.

Follow NBC Latino on Facebook, Twitter and Instagram.