High school graduation rates have improved across the U.S., but not in Oklahoma, recently released data shows.

The 2014-15 data released by the White House Monday shows that graduation rates in the U.S. reached 83 percent. Oklahoma had a rate of 82.5 percent, down 0.2 percent from the previous year.

The state saw a decrease and fell slightly below the national rate, despite the state being above the national rate a year earlier. Oklahoma ranks 30th in the country for high school graduation rates.

Iowa had the highest rate at 90.8 percent, and Washington, D.C. had the lowest with 68.5 percent.

Oklahoma’s graduation rate has continued to decrease since the 2012-13 school year, when it was 84.8 percent.

The state has faced a teacher shortage, and education funding was cut by almost $74 million last fiscal year. However, more than $40 million was allocated to Oklahoma public schools in state surplus funds.

The data released also shows progress for all reported demographic subgroups of students.

The national four-year data is based on the number of students who graduate in four years with a regular high school diploma, divided by the number of students who entered the class four year earlier. The number is adjusted for the number of  students who transfer in and out of the class.