Enrollment in the District’s traditional public schools declined slightly this academic year, breaking six years of consecutive growth, according to figures released this week by the Office of the State Superintendent of Education.

But enrollment in public charter schools grew by 4.5 percent, with those institutions accounting for nearly half of all public school students in the District.

D.C. Public Schools — the traditional system run by a chancellor appointed by the mayor — lost 400 students this year, bringing its total enrollment to 48,144 students. This puts the school system short of a 2014 goal of enrolling 50,000 students by 2017, and makes the objective of enrolling 54,000 students within four years a greater challenge.

The city counts students for its final enrollment tally in October. Jennifer C. Niles, the District’s deputy mayor for education, said even though this week’s report showed a decrease, she expects enough students may transfer into traditional public schools by the end of the year that enrollment will inch up.

Niles said she saw promising trends in middle schools and special program schools, such as the science and technology-focused McKinley Middle.

“I don’t see this as doom and gloom,” Nile said. “I would describe [D.C. Public Schools] as remaining steady and our charter schools as making a small increase.”

Enrollment in charter schools — publicly funded but privately operated institutions — grew from 41,506 last year to 43,393 this school year.

Taking into account traditional schools, nearly 92,000 students are attending class in public schools in the District, a 1.6 percent increase.

The enrollment numbers for traditional schools are another blow to that system, which has been embroiled in a graduation controversy. A city-commissioned investigation found that about one in three graduates in 2017 received their diplomas despite missing too many classes or improperly taking makeup classes.

Will Perkins — a research and policy associate at the 21st Century School Fund, an education advocacy organization — called the numbers troubling for the traditional system, noting that enrollment numbers dropped across most grade levels.

The superintendent’s report showed that charter schools had more students (6,929) at the preschool level than traditional schools (5,798). The traditional school system has more kindergartners enrolled than does the charter school system.

In the preschool years, students have to apply through a lottery to secure a slot, even if it is at their neighborhood school. Perkins said if the traditional system guaranteed families preschool slots in their neighborhood schools, it could help the system capture more families.

“I think it is an issue when families start in charter schools, and may never be in their neighborhood schools,” Perkins said.

A D.C. Public Schools spokeswoman said the system plans to add slots for 3- and 4-year-olds.

Despite growth in recent years, enrollment in the city’s traditional public and charter schools remains far below its peak. The student population had been in a steady decline since the 1960s, when about 150,000 students attended the District’s public schools.

By 1995, enrollment had plummeted to about 80,000 students when the D.C. School Reform Act was passed by Congress, paving the way for charter schools to open in the District.

“The steady increases in enrollment we have seen each year for the past nine years are encouraging signs of the progress we are making in public education,” State Superintendent Hanseul Kang said in a statement.