The profile of immigrants who enter and stay in the United States without government permission is changing.

They’re more fluent in English. And better educated.

A new analysis by the Pew Research Center, the nonpartisan institute in Washington, shows that in 2016, one-third of adult undocumented migrants were proficient in English, meaning they either spoke only English at home or described themselves as handling the language very well.

That’s up from only a quarter of migrants in 2007.

During the same time, the share of undocumented immigrants ages 25 to 64 who had college degrees grew from 15 percent to 17 percent, reported Pew senior demographer Jeffrey Passel and senior writer and editor D’Vera Cohn.

That’s slow to moderate growth. But among recent arrivals — those who have been in the country five years or less — the changes were dramatic.

The share of newer immigrants with college degrees hit 30 percent in 2016, up from 17 percent in 2007. Meanwhile, the percentage of recent undocumented immigrants who lacked high-school degrees fell from 44 percent in 2007 to 31 percent in 2016.

The research arrives as President Donald Trump has again characterized the U.S. as being “invaded” by huge numbers of “illegal aliens” who overwhelm schools, crowd hospitals, and commit crimes.

“Gang members, smugglers, human traffickers, and illegal drugs and narcotics of all kinds are pouring across the southern border and directly into our communities,” the president asserted last week in threatening new tariffs on Mexican goods.

Immigration has been a central issue of Trump’s presidency, as he battles with “sanctuary cities” like Philadelphia, and it promises to be key to his re-election campaign.

Philadelphia is home to about 50,000 undocumented immigrants, according to an earlier Pew analysis.

The percentage of the city’s foreign-born population doubled between 1990 and 2017, to 13.8 percent. China is far and away the primary sending country, with 22,140 city residents, who make up about 11 percent of the foreign-born population, according to a Pew Charitable Trusts analysis of census data. Next is the Dominican Republic with 13,792, followed by Jamaica, 13,500; India, 11,382; and Vietnam, 10,132.

The new Pew analysis said that overall, those who entered the country without permission remained less likely than lawful immigrants to be proficient in English, by 34 percent to 57 percent, or to hold college degrees, at 17 percent to 37 percent.

The researchers attributed the changes that have occurred since 2007 to an evolution among those who are coming to the U.S.

Among newer arrivals, 32 percent were proficient in English in 2016, compared with 18 percent in 2007. Undocumented immigrants who have been in the country for more than a decade also improved their English, but the change was less significant.

Newer arrivals are more likely to hold college degrees, as compared with longer-term residents, a gap that has widened over time. The share of longer-term immigrants with college degrees edged up slightly from 10 percent in 2007 to 11 percent in 2016, the analysis said.

The changing mix of home countries played an important role, as did increasing levels of schooling around the world.

Specifically, the study said, a smaller share of recent arrivals has come from Mexico, whose immigrants have lower levels of English proficiency and education. A higher share of newcomers is coming from Asia, where migrants have more English ability and formal learning.

Most undocumented immigrants from Mexico have not completed high school, and only 4 percent had college degrees in 2016. The numbers are similar for El Salvador, Guatemala and Honduras, from which people have fled violence and poverty.

Among undocumented immigrants from Asia, 64 percent had college degrees in 2016, up from 53 percent in 2007.

Undocumented people who struggle to speak English are more likely to be impoverished, and to live in communities in high-immigration states such as California, Texas, New York, and New Jersey, the analysis said.

An estimated 10.7 million undocumented migrants live in the U.S., down from a peak of 12.2 million in 2007, according to Pew. That’s mostly due to a decline among migrants from Mexico, who made up half of all undocumented people in 2016, down from 57 percent in 2007.