Proportional circle maps

This proportional circle map uses data based off of the 1990 census showing the American Indian Population of these select states. The different circles represent different amounts of American Indian Population in these states. The population is represented heaviest in these lower states, as shown by the really large circles.

http://www.google.com/imgres?imgurl=http://www.neiu.edu/~nerobert/Circle%2520Map.jpg&imgrefurl=http://www.neiu.edu/~nerobert/Cartography.htm%3Fsrc%3Dmappery&usg=__zII9Y8MbQoNNqp_RgoQxvw_HRIM=&h=539&w=640&sz=83&hl=en&start=4&itbs=1&tbnid=Puid02g864UhgM:&tbnh=115&tbnw=137&prev=/images%3Fq%3DProportional%2Bcircle%2Bmaps%26hl%3Den%26sa%3DG%26gbv%3D2%26ndsp%3D21%26tbs%3Disch:1