 The number of people under the age of 18 fell in 17 of Washington's 21 population centers between 2020 and July of last year. According to the Seattle Times, Oak Harbor's child population dropped by 7.5%. Seattle's fell by 3.6%. However, the number of kids rose in four places, Ellensburg, Shelton, Pullman, and Centralia. Eric Hines, Northwest News Radio.