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Most King County offices will be closed on Thursday and Friday, Nov. 22-23, 2018, for the Thanksgiving holiday.  
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Data and Reports

King County residents and elected officials depend on accurate data to conduct business and to make better decisions about county products and services. Staff of  Performance, Strategy and Budget (PSB) are dedicated to providing reports and analysis that standardize the data used within King County and promote good decision-making.

Our Services: 

The county demographer and other staff within PSB prepare a set of annual and periodic reports about King  County characteristics and trends. These reports draw on national and local sources, and they provide interpretive analysis of the application of these data sources within King  County. Currently, there are four series of data reports, as described below. In addition, the demographer responds to hundreds of data requests each year from within and outside  King  County government.

Demographic Presentation A presentation to the King County Council describes recent demographic trends and the current ethnicity, language and income characteristics of King County residents.

Demographic Information:  In 2011 the U S Census Bureau released population counts from the 2010 Census that confirm Washington State and King County growth in recent years. In April 2010, the Census counted 1,931,249 people in King County. In the years since 2010, the Washington State Office of Financial Management (OFM) has published annual population estimates for Washington counties and cities. OFM's estimate of King County's 2018 population is 2,190,200.

In the years since the 2000 and 2010 decennial Censuses, the US Census Bureau has conducted a new sample of population characteristics called the American Community Survey (ACS). Tables of recent ACS data are available for  King  County, summarizing demographic, economic, social and housing characteristics.

Demographic Services:   In addition to the report series listed above, the county demographer prepares occasional bulletins and reports on demographic subjects, for King County and its communities.  Data are available from the 2000 and 2010 US Census, recent surveys from the US Census Bureau, and other sources.  See

King County Buildable Lands Report: In 1997, the Washington State legislature adopted the Buildable Lands amendment to the Growth Management Act, (RCW 36.70A.215). The amendment requires six  Washington counties and their cities to determine the amount of land suitable for urban development, and evaluate the capacity for growth, based upon measurement of five years of actual development activity.  King  County and the other five counties were required to report to the State by September 1, 2002 and every five years thereafter.

Archive: King County Annual Growth Report: The King County Annual Growth Report was launched in 1983 to document population and land development data for King County, its cities, and its unincorporated areas. The County plans to produce an updated growth report in late 2017.

2008 Annual Growth Report

Note: The past years' King County Annual Growth Reports are available for viewing in Adobe Acrobat .pdf format. You will need to have a copy of Adobe Acrobat Reader installed on your computer to view the report files. You can download a free copy of the Acrobat Reader here or visit Adobe's site to get more information.

Archive: King County Benchmark Report:  In 1995, elected officials and citizens throughout the County helped develop a set of 45 indicators, which directly relate to the policies in our countywide Growth Management plans. Our Benchmark Report reviews how we are doing on each indicator, giving us a broad-brush picture of our quality of life. Through the Report we've tried to find objective ways to determine if our quality of life is getting better or worse at the community level.

For more demographic information, please contact: 

Rebeccah Maskin
Demographic Planner

Performance, Strategy and Budget

(206) 263-0380

  Text for screen readers King County Quick Facts