Non-citizens accounted for 64 percent of all federal arrests in 2018, according to new data released on Aug. 22 by the Justice Department. The surge was driven largely by immigration-crime arrests, which have soared to the highest level in at least two decades.

Federal authorities conducted 108,667 arrests for immigration crimes in 2018, up more than five times from the 20,942 arrests in 1998. Immigration arrests accounted for 95 percent of the total increase in the number of federal arrests over the past 20 years, the data shows.

That data also shows a spike in the percentage of arrests of non-citizens compared to arrests of U.S. citizens. In 1998, arrests of citizens accounted for 63 percent of the total arrests. In 2018, the ratio flipped, with arrests of non-citizens growing to 64 percent of the total.

In a press release accompanying the data, the Bureau of Justice Statistics (BJS) noted that while non-citizens accounted for 7 percent of the U.S. population, they committed 24 percent of all federal drug arrests and 25 percent of all federal property arrests and 28 percent of all federal fraud arrests.

President Donald Trump campaigned on a promise to enforce the nation’s immigration laws. While the total number immigration arrests in 2018 reached the highest level in 20 years, the total number of arrests in 2017 was the lowest in 10 years. The increase in total arrests in 2018 was fueled almost entirely by immigration arrests.

“The main driving force for the spike in immigration arrests has been the spike in illegal immigration, and the Trump policies that imposed consequences on illegal crossings a way to try to curb the huge influx of Central Americans and others,” Jessica Vaughan, the director of policy studies for the Center for Immigration Studies.

“Nearly all the immigration prosecutions took place in the districts that include the US-Mexico border. The consequences are important – we know from experience that when illegal crossers have to spend time in jail and face a bar to re-entering, then they don’t keep trying to come illegally,” Vaughan added.

While the report does not separate the legal aliens from illegal aliens, federal incarceration statistics show that 93 percent of aliens in federal custody last year were illegal.

Non-citizens from Mexico and Central America accounted for 94 percent of the immigration arrests last year. Arrest of non-citizens from Central America soared 160 percent compared to 2017, while arrests of those from Mexico grew 48 percent. Notably, federal authorities arrested more Mexican nationals last year than American citizens.

“Federal arrests of Central Americans rose more than 30-fold over two decades, from 1,171 in 1998 to 39,858 in 2018,” the BJS stated.

Further highlighting the role of immigration enforcement in the arrest statistics, the BJS statement noted that the portion of all arrests that occurred in districts along the U.S.-Mexico border has nearly doubled over the course of two decades from 33 percent to 65 percent.

“In 2018, a quarter of all federal drug arrests took place in these five districts,” the BJS statement says. “The number of Central Americans arrested in these five districts almost tripled in one year, rising from 13,549 in 2017 to 37,590 in 2018.”

In terms of prosecutions, more than 78 percent of non-citizens were prosecuted for illegal reentry, alien smuggling, misuse of visas. The most common prosecutions of non-citizens outside of immigration-related offense dealt with drugs, at 13 percent of the total, and fraud, at 4 percent.