Enrollment in the state’s largest school district continues to decline slightly as the population ages and new construction in the district’s territory remains tepid.

Officials with the Anoka-Hennepin School District — using birth records, building permits and census data — are projecting a five-year decline in enrollment.

The district recently released its annual enrollment numbers, and the number of students pre-K through 12th grade was 38,449 on Oct. 1. That’s down 229 students from last year.

The middle and high school population accounted for the declines, losing 244 students. The elementary schools actually added 132 students. The additional loss of students was in other categories, such as special education students, preschoolers or those in night programs.

Enrollment in the district, which covers northern Hennepin and a large swath of Anoka County, peaked at 40,000 in 2004 and has been inching downward ever since.

“If you look at population trends, the number of kids people are having has been declining,” said Neil Klund-Schubert, a principal on special assignment with technology and information services.

But the decline this year wasn’t as steep as projected, Anoka-Hennepin schools officials say. They saw an unexpected bump in the number of third- and fourth-graders, likely due to an influx of younger families. Also, district staff theorize that many families who might have chosen private or charter schools may be staying with the public school system, Klund-Schubert said.

“Some of the trends they are seeing in Anoka County is that it’s starting to get a larger number of younger families when compared to other counties,” he said.

The district is also keeping more 12th-graders enrolled than projected, largely due to online and alternative education offerings as well as more course offerings at the conventional high schools, he added.

According to the district’s more recent projections completed last February, enrollment in grades K-12 will decline from 36,646 this October to 34,805 by the 2017-18 school year.

Those projections do not include prekindergarten programs, some special education students or alternative night programs.

One number that is climbing is enrollment in the free and reduced-price lunch program; 31 percent of students receive them, compared with 18.7 percent 10 years ago, Klund-Schubert said. The number this year is 12,757, up 56 students from last year.

“Part of it is the economy. Families are still hurting,” Klund-Schubert said. More people may now be using the program because parents can enroll online, he said.

“They don’t have to come in and ask for a form and be embarrassed,” he said.