Any city having a population of two thousand and less than thirty thousand may organize as a city under the commission form of government. The requisite population shall be determined by the last preceding state or federal census or the council may cause a census to be taken by one or more suitable persons, in which the full name of each person in the city shall be plainly written, the names alphabetically arranged and regularly numbered in a complete series, verified before an officer authorized to administer oaths and filed with the city clerk.

Census to be conducted in decennial periods: State Constitution Art. 2 s 3.

Determination of population: Chapter 43.62 RCW.