The Washington State Superintendent of Public Instruction (OSPI) has released the most recent data compiled regarding "chronic absenteeism" among schools statewide and Yakima Valley school districts are split down the middle when compared to the state average.

According to the OSPI press release,Chronic absenteeism” is defined as missing 18 or more days of school during a school year... for any reason." Eighteen days represents 10% of the prescribed number of days in a school year.

The state average of K-12 students who are chronically absent per district is 16%.  Eight districts in the Yakima Valley average more than that, while nine fall below that.  Mt. Adams school district leads the entire state with 36.9% of its students missing school regularly while the Yakima school district ranks 11th worst with 23.7%.  Granger comes out best after analyzing the data from the 2014-15 school year with a scant 3.6%

Here are the other 14 plus the aforementioned districts from worst to best:
Mt. Adams - 36.9%
Yakima - 23.7%
Wapato - 22.7%
Mabton - 22.6%
Naches Valley - 19.3%
Grandview - 18.3%
Goldendale - 18.3%
Sunnyside - 16.8%
State average - 16%
Prosser - 14.3%
Selah - 14.1%
East Valley - 13.3%
Toppenish - 13.1%
West Valley - 12.3%
Highland - 11.9%
Zillah - 10.4%
Union Gap - 9.1%
Granger - 3.6%