Census Tracts and Block Groups are shaded according to population density calculated from figures released in the Census Bureau's 2012 American Community Survey data. 

The user can click on census tracts or block groups to view additional data for that area in a popup window, including a pie chart showing race breakdown and a column chart showing age breakdown.
Census Tracts (2012)
Persons Per Sq. Mi. (2012 ACS)
64.86 - 2952.11
2952.12 - 6325.00
6325.01 - 11309.09
11309.10 - 18900.00
18900.01 - 28742.86
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