Arizona fourth-graders have made significant gains on a national standardized science test. They saw the most improvement of any other state on the National Assessment of Educational Progress.

The average score for the state’s fourth-graders increased by 11 points between 2009 and 2015. The number of students who performed at a proficient level also increased by 22 percent.

While the improvement is being celebrated by state education officials, Joe Thomas, the president of the Arizona Education Association, said the results are still sobering as the average fourth-grade score was still four points below the national average.

"I think the teachers are very happy that we’re seeing growth," he said. "I know parents are as well but I just have to imagine what it would look like if we really invested in our kids the way other states do."

Looking inside Arizona, there was no significant difference between male and female student performance in 2015. However, students on free or reduced price school lunch programs did score about 30 points lower on the test than other kids.