The composition of the family has changed drastically over the last 40 years. In 1970, married couples constituted 72% of all households; by 2017 this dropped to just 51%.
While married couple households has decreased during this same period, one-person and non-family households have increased (from 20% to 34% of all families). Single-parent families also grew over the period. In 2017, Yelm had the highest percentage of married couple households (60%) while Olympia had the lowest (36%).