The Arizona Department of Education released AIMS scores and letter grades Thursday for district schools and charter schools throughout the state. AIMS scores showed a slight increase, and half of the district and charter school in the state received grades B and C.

It's the second year the Arizona Department of Education has used the letter grading system to measure school performance.

Out of the 80 graded schools in Pima County, which included school districts and charter schools, 17 received an A, 19 received a B, 24 received a C, and 20 were awarded a D. Tucson Unified School District, the county’s largest, was given a grade of C.

Of the nearly 1,300 schools graded across Arizona, 283 were awarded the top grade compared to 231 last year.

No school district or charter school received a grade of F. The state reserves that grade for those that have been ranked D' schools for three consecutive years.

Also released Thursday were the scores for the Arizona’s Instrument to Measure Standards (AIMS) test.

According to the Arizona Department of Education, science scores from last spring went up 6 percent, math scores increased slightly, and 4 percent more students passed the reading requirement.

Every year, students in grades three to eight and high school sophomores are required to take the AIMS test.

John Huppenthal, the state’s school superintendent, says Arizona students made progress last academic year and he anticipates that progress will continue.