The National Center for Education Statistics reported the U.S. average four-year adjusted cohort rate rose half a percentage point to 84.6 percent. Oregon rose nearly 2 percentage points to 76.7 percent, but only New Mexico at 71.1 percent was lower.
Washington had a 79.4 percent graduation rate, and Idaho had a 79.7 percent rate. Iowa, at 91.0 percent, ranked the highest.
The national graduation rate has been steadily increasing since a change in the counting method for 2013-14, but some states have been accused of artificially inflating their rates through lower standards, easy credit-recovery programs and moving students out of the system. Oregon has among the highest credit requirements.
The Oregon Department of Education released graduation rate data for 2017-18 on Thursday morning as well. Oregon improved 2 percentage points to 78.7 percent, which would still trail most other states.