San Diego Unified has outperformed other urban school districts on a national student achievement test called the Nation’s Report Card, while eighth-grade reading scores for students in California and the country as a whole either stagnated or declined.

That’s according to just-released results from the National Assessment of Educational Progress, a test issued to a sample of hundreds of thousands of students nationwide every two years. The test primarily measures math and reading for fourth- and eighth-graders. It is considered the largest nationally representative and most consistent measure of student performance over time.