D.C. has long been a city divided. But that divide has grown considerably more pronounced over the past two decades.

In a study released today, the Urban Institute mapped D.C.’s 179 census tracts based on whether or not they’re “challenged.” A challenged neighborhood is one whose unemployment rate, share of residents without a high school degree, and share of households headed by a single mother all exceed the citywide average by at least 20 percent.

In 1990, the city’s geographic disparities were already clear. No areas west of 16th Street NW were challenged. And the challenged neighborhoods were predominantly clustered east of the Anacostia River.

But over the next two decades, the challenged patches began to vanish from the neighborhoods west of the river. In 2000, there wasn’t yet all that much change. Parts of Columbia Heights and Park View ceased to be challenged, as did an area near New York Avenue NE that would become challenged again a decade later. The change accelerated between 2000 and the period from 2006-2010, measured by the U.S. Census Bureau’s American Community Survey. The Navy Yard area was no longer challenged; same with Trinidad and Bloomingdale. Meanwhile, the challenged areas became increasingly consolidated east of the river, with new patches in Congress Heights, Washington Highlands, and along Pennsylvania Avenue SE and Southern Avenue SE in Ward 7.

Of the 28 neighborhoods that remained challenged the whole time, 22 are east of the river.

The discrepancy has also played out in the business arena. The map below shows new retail and food establishments that opened between 2000 and 2011. Although every ward has gained establishments, the new businesses opened overwhelmingly west of the river—particularly in wards 1 and 2—and hardly at all in wards 7 and 8:

Maps via Urban Institute