Website Maintenance. A scheduled system maintenance will be perfomed. The website will be down/unavailable from 10:00 am (May 16th, 2012) to 3:00 pm (May 16th,2012). We apologize for any inconvenience this may cause.
Thematic Maps: are data maps of a specific subject or for a specific purpose. Statistical thematic maps include a variety of different map types such as choropleth or shaded maps, dot maps, proportional symbol maps, and isarithmic maps. Special purpose maps generally concentrate on a single theme, such as the Population Centers of the U.S. between 1790 and 2000.