35. Univariate choropleth maps

http://www.clearlyandsimply.com/clearly_and_simply/2009/06/multicolored-choropleth-maps-with-excel.html

A univariate choropleth map is simply a map that is limited to one variable. This map shows what each state commonly calls a generic soft drink, corresponding to the specific color: pop (in clue), soda (in gold) or coke (in red)? Unlike the last post about bivariate choropleth map, this is easier to read and is straightforward. Some more examples of univariate choropleth maps are population density, annual rainfall, birthrates, or any single set of data that is desired.