Last week we talked about the historic population explosion in many of the largest US cities, including Atlanta, so now it’s time to take a look at the Atlanta metro area.

Atlanta’s population burst over the past five years has been spectacular. The city gained 40,000 residents between 2010 and 2015, leading to an increase of over 10 percent. In our previous article we put this number into historical context to show the significance of the achievement. During the great urban exodus of the 1950’s through 1980’s, Atlanta lost around 100,000 residents as more and more people fled for the suburbs. That massive de-population of major American cities has been part of our culture for the past several decades and is considered one of the major cultural shifts in history.

Well, in just the past five years Atlanta gained back nearly half of the 100,000 residents it had lost. Those are growth numbers that haven’t been seen in over 50 years. At this rate Atlanta could set a new population record by the end of the decade, though it’s probably safe to assume that over the next five years the growth rate will decrease as some of the cheaper areas to develop and re-develop disappear.

Let’s take a look at the numbers. The graph below shows the 2015 population for major Georgia cities. Atlanta, Columbus, and Augusta are the three largest cities in the state. Sandy Springs passed the 100,000 mark between 2010 and 2015 and remains the 7th largest city in Georgia.

The next graph shows the growth rate from 2010 to 2015 of all of major Georgia cities. Sandy Springs, Atlanta, and Gainesville stand apart from the pack with all three growing at over 9 percent during that time period. Macon, with a growth rate of -1.2%, was the only major city to decrease in population between 2010 and 2015.

Now let’s look only at Metro Atlanta. The graph below shows the 2015 population for each county in the 10-county metropolitan area along with each county’s population growth rate from 2010 to 2015. Between 2010 and 2015, Forsyth County was by far the fastest growing county in the region with a rate of over 20%. The growth rates of Fulton and Gwinnett Counties are notable since it takes many more people moving into those counties to achieve high growth rates; over that five year time period Forsyth (21.04%) and Gwinnett (11.24%) boasted the highest growth percentages, while Cherokee (10.06%) and Fulton (9.66%) followed closely behind.

The following chart shows the 2010 and 2015 population for major Atlanta area cities. Atlanta, Sandy Springs, Roswell, and Johns Creek are the four metro Atlanta cities with over 75,000 residents.* The figure below shows the growth rate for each city from 2014-2015 and 2010-2015. Sandy Springs, Alpharetta, and Atlanta all grew at rates above 10% for the five year period. No cities lost population between 2010 and 2015, but from 2014 to 2015 East Point and Marietta both decreased in population.

As illustrated by the Population Density figure below, Brookhaven is by far the densest major city in the metro area with just over 6,700 people per square mile. However, it’s also the smallest city at just 7.7 square miles. Dunwoody, Smyrna, and Atlanta round out the next grouping of cities with all three ranging between 3,500 and 3,700 people per square mile. To put this into context, New York City’s density is over 28,000 people per square mile and Miami’s is around 11,000 people per square mile. So we’re talking relatively low numbers here in metro Atlanta.

The most surprising city may be Johns Creek. While 2,700 people per square mile certainly wouldn’t be considered dense compared to some areas of  Atlanta or any other larger city, it is fairly high for a city so opposed to transit. This is a city that led the movement to stop MARTA from expanding into North Fulton County, yet it has more people per square mile than Roswell and Marietta and it’s right up there with Sandy Springs in terms of density. These are three cities that are much more transit-friendly than Johns Creek.

To put the numbers into even more context, below are two density maps by census tract of Atlanta, Sandy Springs, Dunwoody, and Brookhaven. These are maps we used in a previous article comparing Atlanta’s MARTA rail to DC’s Metrorail. While Atlanta as a whole is not all that dense, many neighborhoods in the city’s core are three to five times as dense as Brookhaven. For instance, the Peachtree corridor from downtown to Midtown has density levels between 7,200 people per square mile and over 29,000 people per square mile. This area dwarfs density numbers throughout North Fulton and East Cobb.

Finally, how does county data and city data stack up? Below are two charts showing each jurisdiction’s population along with its share of the total 10-county metro area’s population in 2015 and in 1990. The population of the cities we’ve been tracking has been excluded from their respective county’s population numbers to produce a better representation of the weight of each political entity.

Fulton County’s population in the charts below is the county’s population without Atlanta, Roswell, Alpharetta in the 1990 chart and its population without Atlanta, Roswell, Alpharetta, Johns Creek, and Sandy Springs in the 2015 chart.

Cobb County’s population is the county’s population without Smyrna and Marietta for both the 1990 and 2015 charts.

Gwinnett County’s population is the county’s population without Peachtree Corners in the 2015 chart and the county’s total population in the 1990 chart.

Dekalb County’s population is the county’s population without Atlanta in the 1990 chart and the county’s population without Atlanta, Brookhaven, and Dunwoody in the 2015 chart.

Now lots of smaller cities exist in each county, but these are the major players in the Atlanta metro area.

Overall, 23% of metro Atlanta area residents live in one of the major metro Atlanta cities. Excluding the major cities from all the counties results in Gwinnett County, without Peachtree Corners, having the largest share of the area’s population at 19%. It also makes Atlanta the fourth largest jurisdiction in the area and vaults Cobb to the number two position.

There are a few notable changes that occurred between 1990 and 2015. The first is the addition of new major cities. Sandy Springs, Johns Creek, Peachtree Corners, Brookhaven, and Dunwoody were all chartered as cities within the last 10 years. The second is Atlanta’s significant drop in its share of the total area population; it fell from 16% in 1990 to 10% in 2015. In that 25 year time period it added just 70,000 residents, though 40,000 of them were added in just the last five years.

The other major change is the swap in the share of the area population between Dekalb County and Gwinnett County. In 1990, Dekalb had 20% of the area’s population while Gwinnett accounted for 14%. Fast forward to 2015 and the two have traded spots with Gwinnett now accounting for 19% of the population and Dekalb holding 14% of the population. In that time period Gwinnett County added a staggering 500,000 people while Dekalb County added about 200,000, though roughly 75% of those 200,000 people were in Atlanta and the newly created cities of Dunwoody and Brookhaven.

Fulton County’s share has fallen from 9%  in 1990 to just 5% in 2015. Most of the growth that has occurred in the county has been in Atlanta and the new cities of Sandy Springs and Johns Creek, with the latter two accounting for about 200,000 residents in 2015. All in all, Fulton County still represents 22% of the area’s population when we include the residents of all of its cities. This and other data can be found in a post we did several weeks ago looking only at county-level population data.

*This article was corrected on June 7, 2016 to include Johns Creek as a metro Atlanta city with over 75,000 residents.