DES MOINES, Iowa (AP) — Iowa’s Education Department says the state’s high school graduation rate has increased for the fifth year straight, even as dropout rates increased slightly for the first time since the 2009-10 school year.

In a news release Tuesday, the department said 91.3 percent of students in the 2016 graduating class graduated within four years, up from 90.8 percent from the previous year. Iowa’s annual dropout rate was 2.8 percent last year, up from 2.5 percent the previous year. The latest dropout rate represents 4,154 students in grades 9-12.

Officials say graduation and dropout rates can increase simultaneously because they measure different groups. The graduation rate follows one class for four years, while annual dropout rates represent the number of students who dropped out of grades 9-12 during one school year.