Age Distribution

• Age Distribution Over Time
• Age Distribution by race and ethnicity
• Age Distribution by Subregion
• Gender and Age Distribution
• Age Dependency Ratio

Longitudinal Trends (2000, 2006, 2011):

• Age category 45-49 is the first group showing an increase in percentage.

• All but one category above age 45 is showing an increase in percentage of the total King County population.

• Data indicates that the rate of King County children (age 0-6) is in a slight decline.

• Several age categories from age 18-44 are also in decline.

Read a caution on interpreting this data

Key Data

Download Data | Source: Claritas 2006 Update (Census Tract Level)

Age 25-34

• This population saw the biggest decrease in age distribution with a loss of 29,833 (10.1%) between 2000 and 2006.
• This age group made up 17.0% of the population in 2000 and is down to 14.7% in 2006.
• It is estimated to decline to 12.3% of the population by 2011.

Age 21-24

• This population experienced the second largest decrease with 7,964 fewer people, a decrease of 8.5%.
• This age group represented 5.4% of the population in 2000, 4.7% in 2006 and is estimated to be down to 4.6% in 2011.

Age 55-59

• Age 55-59 grew as the largest percentage of the total King County population increasing from 4.8% to 6.5% between 2000 and 2006, an increase of 34,394.
• In 2011 this population is estimated to represent 7.4% of the population.
• The 2000-2006 growth rate is 41.2%.

Age 60-64

• Edging out the 55-59 age group, the 60-64 age group witnessed the largest percentage increase with 46.6% between 2000 and 2006.
• In 2000 this population represented 3.3% of the age distribution; in 2006 it was 4.7%; and in 2011 it is estimated to be 6.1%.

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Age Distribution By Race and Ethnicity

Download Data | Source: Claritas 2006 Update (Census Tract Level)

Age Distribution By Subregion

A look at age distributions allows assessment of the concentrations of people moving through various life stages. First is the 0-6 age grouping showing the population where childcare, early development and early elementary school are seen as major issues. This is followed by the school age 7–17, where academic achievement, maturing and transition towards adult life are taking place. Next is the 18-64 age range, representing the traditional working and parenting group. Age 65+ is the life stage where people are finishing careers, planning for, entering and living in retirement. Further analysis of these life stages can be found under the heading Age Dependency Ratio.

Download Data | Source: Claritas 2006 Update (Census Tract Level)

Age 0-6

• There are 146,597 0-6 year olds.
• Represents 8.1% of the population.
• Population ranges from 6.1% in Seattle to 9.6% of the South King County population.
• Between 2000 and 2006 this age group has declined by 2.1% and is estimated to decline by 3.2% when looking at the 2000–2011 results.

Age 7-17

• Age 7-17 includes 239,579 youth.
• This represents 13.3% of the King County population.
• South King County has the highest percentage with 15.6% while both North and East are tied at 14.7% and Seattle has the lowest rate with 9.3% of its regional population falling in this age group.

Age 18-64

• This age distribution is traditionally referred to as the working years.
• The distribution includes 1,223,013 persons.
• This age group makes up 67.7% of the population.
• Seattle has the highest concentration with 72.8% of the population. The balance of the county was all within 2% of the average. 

Age 65-84

• This age distribution currently includes 165,744 persons.
• This age group makes up 9.2% of the population.
• In both Seattle and North King County this population represents 9.6% of the age distribution.  East King county is at 9.3% with South County reporting the lowest percentage at 8.6%. 

Age 85+

Age 85+ is sometimes lumped in with the 65-84 age range but planners are taking note that the health, mobility and financial realties of this age group are distinct from the younger retirees

• This age group includes 30,528 persons.
• This group represents 1.7% of the population.
• South King County reports the lowest percentage at 1.3% and Seattle having the highest population at 2.3%.

Gender and Age Distribution

Download Data | Source: Claritas 2006 Update (Census Tract Level)

• The female population currently represents 50.1% of the King County population leading men by less than 5,000 persons.

• Beginning with the distribution from age 65, women become the majority, outnumbering males by 28,214. Females make up 57.2% of this population.

• In the population age 85 and older, females outnumber males by 11,224. Females make up 68.4% of the total population for this age distribution.

Source:  Public Health - Seattle & King County

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Age Dependency Ratio

One method of anticipating the potential impact of the distribution of ages of the population is to examine the Age Dependency Ratio (ADR). The ADR formula assumes that the greater the number of people less than age 18 and over 64 the greater the economic load traditional working age people age 18 to 64 will have to carry. The ADR calculation divides the sum of youth (0-17) and old adults (65+) by the population age 18 to 64 multiplying the result by 100.

Key Facts

• ADR appears fairly steady over time, beginning in 2000 with an ADR of 49.2 then dipping to 47.6 in 2006 before increasing to 49.3 in 2011.
• Because the ADR combines both the youth population and older adult population as a single ratio, the changes in these sub-populations is understated when rolled up.

Youth ADR (0-18)

• Population is in a slow decline going from 390,646 in 2000 down to an estimated 385,258 in 2011.
• In turn, the Youth ADR has dropped from 33.5 to 30.7 in this time frame.

Older Adult ADR (65+)

• Over the same period the first wave of baby boomers is beginning to turn 65 and is starting to register in the Older Adult ADR.
• In 2000 the population was 181,772 and by 2011 it is expected to be 233,183, changing the Older Adult ADR from 15.6 to 18.6.

 Download Data |Source: Claritas 2006 Update (Census Tract Level)

The adjustments in these two populations mean the traditional working population continues to support approximately the same ratio of dependents, but the mix and resulting long-term ramifications call for a vastly different set of services and supports. Over time, the dual affects of the baby boomers exit from the workforce and the vast improvement in life expectancy rates will also continue to impact the growing size of the older adult ADR population.

• Overall Washington State ADR was ranked # 48 in the nation with an ADR of 55.1% while the national average is 60.0% in 2005.

• The overall ADR has decreased from 2000 to 2006 but is expected to increase by 2011.

• The decrease has been due to a lower 0-18 age group which has declined from 33.5% of the ADR to 31.6% in 2006 and is projected to further decline to 30.7% by 2011.

• The Older Adult ADR has been gradually increasing. In 2000 the Older Adult ADR was 15.6%. That ratio has increased to 16.0% in the last six years and is projected to equal 18.6% by 2011.

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