Younger workers are taking over the jobs market in many cities.

At least it can seem that way, according to a CareerBuilder study on which cities are gaining—and losing—the most millennials, and which have the most rapidly aging workforce.

Related: We don’t have to be flat broke in retirement

Young people looking for work in their chosen fields—or, sometimes, for any work at all—are increasingly gravitating toward some cities while leaving others behind.

That could be due to the job market, affordable housing or a host of other reasons.

Related: Many millennials want to stick with one company

This young workforce often brings with them the latest in training and education, but younger workers may lack basic knowledge in other areas. Employers who are shedding older workers in an effort to save money on salaries and benefits are losing a valuable opportunity to take advantage of older workers’ experience.

If employers are hanging onto older workers but relegating them to lower-paying jobs and otherwise impeding their efforts to fully retire, they’re only making it harder to build a younger workforce.

That’s because workers stuck in lower-paying jobs often fail to make enough money to set anything aside for retirement—and thus are likely to remain in the workforce as long as they are physically capable of doing so.

Employers who offer a retirement plan, even—and perhaps especially—to younger workers can ensure that when they are ready to leave the workforce, employees will be financially prepared to do so.

Such an action could also ensure that an influx of suitable young candidates will continue to be available as the years pass.

“Whether they are motivated by financial reasons or personal choice, pThis city, with its Frank Lloyd Wright Center pictured, is number 1 in terms of increase in millennial workers.(Photo: AP)eople are staying in the workforce longer,” Matt Ferguson, chief executive officer of CareerBuilder, said in a statement.

Ferguson added, “At some point those workers and their intellectual capital will retire, so a city with a workforce that is aging at a faster rate needs to ensure it is attracting an adequate supply of new talent to fill the gap and fuel economic growth. While big cities have broad appeal, younger generations are also gravitating toward second-tier markets with diverse economies, a strong technology presence and affordable cost of living.”

Related: Part-time work for older employees: Yes or no?

And while below we offer the 10 cities where millennials are seeking their fortunes, it’s also interesting to note which cities are losing millennials at the fastest rate—meaning that businesses might be disadvantaged in the future when they seek to replace retiring workers and have a smaller pool of candidates to draw on.

Cities experiencing the biggest declines in millennial workers since 2011 include Tucson, Arizona; San Diego, California;  and Toledo, Ohio.

None of the 10 most populous cities experienced a decline during this period.

And interestingly, while San Diego has a high concentration of younger workers, it’s also among the cities that have experienced the greatest exodus of millennials from its workforce since 2011—rather like a revolving door.

Whether the workers in your city are young, old, or a fortunate blend of the two, here’s a look at the cities whose workforces are gaining the most millennials.

 

San Jose underpass with public art display; this city is increasing in millennials. (Photo: AP)

10. San Jose-Sunnyvale-Santa Clara, California

 

Total Population in 2016: 2,001,817

Share of Workers Ages 22-34 in 2016: 27.0 percent

Change in Share of 22-34 Workers, 2001–2016: 1.4 percent

 

9. Nashville-Davidson–Murfreesboro–Franklin, Tennessee

 

Total Population in 2016: 1,858,130

Share of Workers Ages 22-34 in 2016: 29.9 percent

Change in Share of 22-34 Workers, 2001–2016: 1.5 percent

 

Urban Honolulu is increasing in millennial workers. (Photo: AP)

8. Urban Honolulu*, Hawaii

 

Total Population in 2016: 1,006,973

Share of Workers Ages 22-34 in 2016: 30.8 percent

Change in Share of 22-34 Workers, 2001–2016: 1.5 percent

 * The Census Bureau’s Honolulu Census Designated Place (CDP) was separated in 2010 into 3 areas: Urban Honolulu  CDP, East Honolulu CDP, and a portion placed in the already existing Hickam CDP.

7. Richmond, Virginia

 

Total Population in 2016: 1,283,671

Share of Workers Ages 22-34 in 2016: 28.3 percent

Change in Share of 22-34 Workers, 2001–2016: 1.5 percent

 

Augusta, Georgia, known as the setting for the Masters Golf Tournament, is, with Richmond County, South Carolina, adding millennial workers. (Photo: AP)

6. Augusta-Richmond County, Georgia/South Carolina

 

Total Population in 2016: 594,377

Share of Workers Ages 22-34 in 2016: 30.0 percent

Change in Share of 22-34 Workers, 2001–2016: 1.6 percent

 

5. Austin-Round Rock, Texas

 

Total Population in 2016: 2,051,270

Share of Workers Ages 22-34 in 2016: 32.3 percent

Change in Share of 22-34 Workers, 2001–2016: 1.6 percent

 

The region including Allentown-Bethlehem, PA, and Easton, NJ is adding millennial workers. (Photo: AP)

4. Allentown-Bethlehem-Easton, Pennsylvania/New Jersey

 

Total Population in 2016: 835,117

Share of Workers Ages 22-34 in 2016: 26.2 percent

Change in Share of 22-34 Workers, 2001–2016: 1.7 percent

 

3. Colorado Springs, Colorado

 

Total Population in 2016: 707,073

Share of Workers Ages 22-34 in 2016: 31.6 percent

Change in Share of 22-34 Workers, 2001–2016: 2.0 percent

 

El Paso, Texas, on the border with Juárez, Chihuahua, Mexico, is seeing an increase in millennial workers. (Photo: AP)

2. El Paso, Texas

 

Total Population in 2016: 847,282

Share of Workers Ages 22-34 in 2016: 32.3 percent

Change in Share of 22-34 Workers, 2001–2016: 2.1 percent

 

1. Madison, Wisconsin

 

Total Population in 2016: 647,860

Share of Workers Ages 22-34 in 2016: 30.3 percent

Change in Share of 22-34 Workers, 2001–2016: 3.1 percent

While Madison has experienced the greatest increase in the share of workers ages 22-34 from 2001 to 2016, Provo, Utah has the highest overall share of millennial workers; 35.4 percent of its workforce was aged 22–34 in 2016, roughly the same as in 2001 and 2011.

Other top-ranking cities with the greatest overall share of millennial workers include El Paso, Texas (32.3 percent), Austin, Texas (32.3 percent), Salt Lake City, Utah (32.2 percent) and San Diego, California (31.9 percent).

Among the 10 most populous cities, San Francisco, California, New York, New York and Atlanta, Georgia saw the biggest increase in millennials since 2011.