The term specific gravity, symbolized sp gr, refers to the ratio of the density of a solid or liquid to the density of water at 4 degrees Celsius. The term can also refer to the ratio of the density of a gas to the density of dry air at standard temperature and pressure, although this specification is less often used.
Households in Columbia, MD have a median annual income of $100,849, which is more than the median annual income in the United States. Look at the chart to see how the median household income in Columbia, MD compares to that in it's parent locations. Dataset: Source:
The Loudoun County, Virginia suburb of Washington, D.C. is the highest-income county by median household income. Another Washington suburb, Arlington County, Virginia, ranks as the highest-income county by median family income. Many of the top counties in the following lists are found in the Northeast Megalopolis, particularly in the Washington metropolitan area and the New York metropolitan area. Median household income American Community Survey. Presented below are the 25 wealthiest counties (with populations of 65,000 or greater) in the United States by median household income according to the 2012 American Community Survey prepared by the US Census Bureau.