Maryland county data was collected from the 2011 Maryland Statistical Handbook. This dataset contains land area, population, population density and per capita personal income (current USD) for each county of Maryland for year 2010. In the visualizations, the red, yellow, black and white were chosen to represent Maryland.
Each box shows the land area of a county while the colors represent per capita personal income. The counties have been grouped by their region. The coloring was done in two equally dense bins with colors representing each end of both the bins.