D.C. Public Schools has reached enrollment numbers not seen since 2006, per preliminary numbers released on Tuesday by the city—more than 50,000 students are enrolled in the system’s public schools this academic year.

But even as the number of students in public schools is growing, charter school enrollment has slipped slightly for the first time since the schools were established in D.C. in 1996, as first reported by the Washington Post. The drop is likely due to five charter schools failing to reopen this fall because of poor academic performance or for other logistical reasons.

The drop is relatively small—about 1 percent, per the city’s press release. There were 43,960 charter students enrolled during the 2018-19 school year, while there are 43,556 students enrolled for the 2019-20 school year. The numbers are preliminary, and the Office of the State Superintendent will release finalized numbers in January 2020.

Things could soon look up for charters, however. Five new charter schools have the go-ahead from the city to open up in the 2020-2021 school year, and two more schools opened up new campuses this year where enrollment could expand, per the Post.

Despite the slight decline in charter enrollment, Mayor Muriel Bowser is touting its DCPS enrollment increase as the result of city policies and practices. “The continued growth at our public schools is proof that if we listen to and work with the community, meet the needs of our students, and build the programming and the facilities that our students need and deserve—then families will come,” Bowser said in a press release on Tuesday. “We’re going to keep investing in our students and teachers to improve the quality of education and keep DCPS and our public charter schools growing for another decade to come.”

This is the 11th straight year that the number of students in D.C. public schools has increased, per the release. 

Even as student enrollment has continued going up, D.C. has had a difficult time retaining teachers. Despite relatively high salaries, teacher attrition in D.C. is at about 25 percent, high above the national average of 16 percent. An auditor’s report last year found that D.C. principals are the most stressed out in the nation.

D.C.’s school enrollment numbers, while growing, are still below their peak of about 150,000 students in the 1960s. The District’s population overall was highest in recorded history during the 1950 census.