More than half of the 4,316 illegal immigrants apprehended by Customs and Border Protection at the U.S.-Canada border last year were Mexican citizens, reports the Washington Examiner.

Total arrests at the northern border jumped 43 percent, reaching its highest level since 2011, according to CBP.

The Examiner also cited CBP data in its report on the arrests of 23,034 illegal immigrants over the past six months at the Southern border with the help of National Guard troops.

President Donald Trump authorized the troops’ deployment last April following the emergence of a caravan of Central American migrants headed toward the U.S.-Mexico border.

Of the eight sectors patrolled by CBP, Detroit saw the most arrests of immigrants at 693, followed by Swanton in Vermont at 563 and Blaine in Washington state at 289.

Human smuggling along the northern border is just as sophisticated as it is at the southern border, according to news reports.

“They are very well organized,” U.S. Border Patrol Agent Richard Ross said. “They have scouted the area. They have scouted us. Basically, we are not dealing with the JV team; this is the varsity.”

The northern border numbers are small compared with the southwest border, with 244,322 apprehended in 2018.