Seattle is known as a city of booms and busts, dating all the way back to our first boom, the Klondike Gold Rush. But over the past 100 years, one thing has remained constant: the suburbs of King County grew faster than the city of Seattle.

Now, with the release of data from the 2020 census, the suburbs’ long run is officially over.

From 2010 to 2020, Seattle’s population grew an incredible 21%, surpassing the 16% growth of surrounding King County.

It’s quite a turnaround.

Census records show that from 1910, decade after decade, the population growth of the surrounding county has outpaced that of the city. Even when the city prospered, as it did in the post-war period, the county prospered more. And when the city’s population stagnated, such as during the Great Depression, or contracted, as during the Boeing Bust of the 1970s, the suburbs still registered impressive double-digit growth.

But the 2010s, referred to as the ‘Decade of the City’, were different. Millennials and empty nesters alike flocked to urban areas, drawn to the appeal of walkable neighborhoods and urban living. Seattle could be the poster child for this trend, with the boom (and gentrification) of many of its urban neighborhoods.

Contributing to the city’s resurgence was explosive job growth during this period, led by Amazon, which relocated its headquarters to the downtown South Lake Union neighborhood in 2010.

Over the decade, Seattle’s population grew by nearly 130,000 to 737,000. The 21% growth rate marks the city’s fastest growing decade since the 1940s, when the population grew by 27% – and it should be noted that some of the growth in the 1940s was due to the city annex areas that are now part of North Seattle. None of the 2010 population growth came through annexation.

Certainly, for the surrounding King County, the 2010s were still a period of growth. The population growth of 16% surpassed the 13% growth of the previous decade. In the 2010s, the suburbs of King County had a population of about 210,000, up to about 1.5 million.

That said, if you compare the 2010s to the suburban growth rates of the 20th century, it’s clear that things have slowed dramatically. For example, in the 1960s, King County outside of Seattle grew by more than 60%, and by the 1940s the population nearly doubled.

Some parts of the province grew much faster than others in the 2010s. I divided suburban King County into seven areas so we could see the different growth patterns in the county and compare them to Seattle.

Interestingly, none of these seven areas grew as fast as Seattle did in the 2010s.

The fastest suburban growth occurred on the Eastside, where the population grew by 112,000, or about 18%. The Snoqualmie Valley, the sparsely populated and more rural area to the east, grew at nearly the same rate at 16%. The slowest growth was on Vashon Island, at just 4%.

Policy probably plays a role in the slower growth in the suburbs in recent decades. The Growth Management Act, passed by state legislatures in 1990, regulates development to curb urban sprawl and protect environmentally sensitive land in high-growth areas. And since the law went into effect, a higher proportion of new housing permits are earmarked for development in the province’s larger cities rather than rural areas.

Census records clearly show that since the 1990s, the overall growth of King County’s suburban areas has slowed significantly.

Of course, we are now in a new decade, a decade that has unfortunately been defined by the coronavirus pandemic. It has especially not been good for cities. In Seattle and other major American cities, the downtown area looks a bit rough these days, with boarded up storefronts and mostly empty sidewalks. There has been a marked increase in homelessness and the homicide rate has risen.

There are already some indications that the trend of the 2010s has reversed, with growth in the suburbs faster than in Seattle. The rise of remote working has made it much easier to live far away from urban job centers.

At this point, it’s probably too early to say how much of the changes from the pandemic will be permanent, or whether Seattle and other cities can recover.