The District is becoming younger, whiter and richer as its neighboring suburbs grow more diverse.

Whites now make up 34 percent of D.C.'s residents -- up from less than 28 percent in 1999 -- while the black population has dropped from 60 percent to 51 percent over the same period, according to the 2007-2011 average released by the Census Bureau's American Community Survey on Thursday. The 2011 American Community Survey released earlier this year showed the city's black population fell to below 50 percent last year.

About 30 percent of residents are within the ages of 20 and 34, up from less than 27 percent in 1999, and median household income has climbed 14 percent to $61,835.

Source: U.S. Census Bureau

At a glance
D.C.. 2007-2011 D.C., 1999 Montgomery County, 2007-2011 Montgomery, 1999 Prince George's County, 2007-2011 Prince George's, 1999 Arlington County, 2007-2011 Arlington, 1999 Fairfax County, 2007-2011 Fairfax, 1999
Whites 202,229 159,178 480,156 519,318 132,621 194,836 129,496 114,489 589,960 624,296
Blacks 304,769 350,455 160,575 142,507 545,650 515,558 16,808 19,425 95,279 90,312
Asians 20,645 17,956 131,693 107,785 34,854 35,450 19,107 18,666 184,783 140,224
Hispanics 53,372 44,953 158,814 100,604 124,454 57,057 30,256 35,268 160,366 106,958
Median household income $61,835 $54,164 $95,660 $96,581 $73,447 $74,585 $99,651 $85,040 $108,439 $109,403

Those changes go hand-in-hand with shifting populations in the Washington suburbs. As the percentage of white residents drops in Montgomery and Fairfax counties, black, Asian and Hispanic populations are on the rise. Montgomery is 50 percent white, according to the latest census data, down from nearly 60 percent in 1999, while Fairfax dropped from 64 percent to 55 percent. Median incomes fell.

Howard University sociology professor Roderick Harrison said the suburbs' better public school systems generally draw older residents with children out of the cities. Jobs in growing sectors like defense, medicine and information technology attract residents with high education levels -- which includes many Asians. That, in turn, increases the need for blue-collar and manual labor, which lures Hispanics, Harrison said.

Those demographic shifts are part of a nationwide trend, he said. But the region's

pattern is even more pronounced because its government jobs and related industries have allowed it to weather the recession better than other cities.

"The metro area can consider itself fortunate that it's experiencing this kind of health," Harrison said. "The D.C. metro area has attracted a very highly educated professional labor force, and even through the recession the job markets have remained very robust."

With the shift comes new development. Dan Silverman, who moved to the District 15 years ago and writes about its neighborhoods for his blog, PoPville, has witnessed the changes in his own neighborhood of Petworth and around the city.

"When I first came to D.C., people said to be careful if you go east of 16th Street. 16th Street!" Silverman said. "Now you would laugh if people told you that."

Higher incomes mean more money to spend, and Silverman pointed to the wealth of new dining and entertainment options in neighborhoods like U Street, Logan Circle and Columbia Heights.

"You see tons of new bars and restaurants, you see these gigantic buildings going up that were never there before," he said. "Now people from the outside are recognizing what a good place it is to open up businesses."

Prince George's County, meanwhile, has served as a rallying point for many blacks who have moved out of the District.

"There's a large gentrification effort that has occurred over the years in D.C., and that's pushing folks out," said County Council Chairwoman Andrea Harrison. "We've gone from a very rural and a very suburban county to more of an urban-suburban county."

Those D.C. ties are hard to sever, though. Roderick Harrison said jobs, church congregations and community organizations will keep new Prince George's residents coming back. As young, white professionals make their mark in D.C., he thinks the effect on the departing black middle class will be a big question.

"What happens to a middle class that no longer has that geographic anchor?" he asked. "Does it still accomplish the things that it historically has?"