There are 17 US Post Offices in Howard County serving a total of 235,228 residents equating to 13,837 residents per post office. It's estimated that approximately 375,450 packages are handled across the 17 county post offices annually. Howard County is a county located in the central part of the U.S. state of Maryland. As of the 2010 census, the population was 287,085. Its county seat is Ellicott City. Howard County is included in the Baltimore-Columbia-Towson, MD Metropolitan Statistical Area, which is also included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. However, recent development in the south of the county has led to some realignment towards the Washington, D.C. media and employment markets. The county is home to Columbia, a major planned community of approximately 100,000 founded by developer James Rouse in 1967. Howard County is frequently cited for its affluence, quality of life, and excellent schools. With an estimated median household income of $108,844 in 2012, Howard County had the third-highest median household income of any U.S. county in 2013. Many of the most affluent communities in the Baltimore-Washington Metropolitan Area, such as Clarksville, Dayton, Glenelg, Glenwood, and West Friendship, are located along the Route 32 corridor in Howard County. The main population center of Columbia/Ellicott City was named second among Money magazine's 2010 survey of \"America's Best Places to Live.\" Howard County's schools frequently rank first in Maryland as measured by standardized test scores and graduation rates. In 2010, the center of population of Maryland was located in the Howard County town of Jessup.