Those scores are based on state tests that students took last spring, including the California standards tests and the high school exit exam.
81 percent of Fresno Unified schools ranked in the bottom half statewide; the number is nearly 70 percent for all central valley schools. That includes 86 percent of the schools in Madera Unified and 73 percent of the schools in both Visalia Unified and Central Unified.
Just 5 percent of Clovis Unified schools ranked in the bottom half.
17 valley schools ranked in the state's top 10 percent, including 13 in Clovis unified.
There's a second set of rankings that compares schools that have similar demographics, such as poverty or the number of students learning English.