The number of people locked up in the United States continued a recent trend of modest decreases in 2016. Along with a one percent decline to the total number of people in a state or federal prison, the nation’s population of immigration prisoners also dropped, data released by the federal government this week reveal.

People sentenced to federal prison for at least one year dropped 1.4 percent to 1,505,397 people, the Bureau of Justice Statistics reported. Of those, 189,192 were in the custody of the Federal Bureau of Prisons due to conviction for a federal offense. Approximately twenty-one percent of those federal prisoners (39,956) were not United States citizens. The government data doesn’t disclose how many non-citizens were confined because of an immigration crime. It also doesn’t include people locked up pending prosecution for a crime or under the custody of the Department of Homeland Security pending removal proceedings in immigration court.

Overall, though, the data indicate that 7.7 percent, or 13,300 people, were imprisoned for an immigration crime on September 30, 2016. The BJS typically takes a single-day snapshot approach to its statistical reporting. Not surprisingly, a larger share of the imprisoned Latino population was there due to immigration activity. For Latinos, 22.7 percent (12,700 individuals) were imprisoned by the BOP due to an immigration crime.

The BJS report sheds light on federal law enforcement trends. Stretching to the Bush administration and continuing uninterrupted through President Obama’s eight years in office, immigration crimes have occupied a large presence in federal prosecutorial priorities. In 2016, for example, federal prosecutors charged more people with immigration crimes than any other type of federal crime by a substantial margin. That year, 68,314 defendants were pinned with an immigration charge compared to the next highest category of offense, drug crimes, which were lodged against approximately 24,000 people.

Prosecutorial trends inevitably show up in prison population counts. Back in 1990, very few people were in federal prison because of an immigration crime. Ten years later, there were 13,676 people imprisoned for that reason. Last week’s report indicates that 2016 saw the fewest number of immigration prisoners since the last year of the twentieth century. In 1999, the federal prison system housed 10,156 convicted immigration offenders.

President Trump has made much of his administration’s desire to target immigration law violators. Under Attorney General Sessions, the Justice Department has prioritized criminal immigration prosecutions. Indeed, in an April 2017 speech, Sessions claimed “criminal aliens…seek to overthrow our system of lawful immigration.” The Justice Department, he added, would “take a stand against this filth.”  He asked federal prosecutors to do their part by emphasizing prosecutions of five immigration crimes. The data released last week do not cover the Trump presidency so it is too early to weigh in on Trump era trends.