Other national surveys. 1  In 2015, the National Survey on Drug Use and Health reported that 20% of youth aged 12 to 20 years drink alcohol and 13% reported binge drinking in the past 30 days.8.
Mercer Island, WA Population and Races. As of 2010-2014, the total population of Mercer Island is 23,636, which is 7.26% more than it was in 2000. The population growth rate is much lower than the state average rate of 17.05% and is lower than the national average rate of 11.61%.
The Mercer County population density is 1,614.44 people per square mile, which is higher than the state average density of 1,017.40 people per square mile and is much higher than the national average density of 82.73 people per square mile.