Continuously Variable Proportional Circle Map

http://personal.frostburg.edu/krtopping0/maps.htm

Continuously variable proportional circle map are used to represent data. The circles within the maps represent the proportion of the data being measured. For example, if crime rates within areas were being measured. There would be larger circles in areas with higher crime rates and in areas of lower rates there would be smaller circles. The map above measures the number of people killed in road accidents in Europe in 2000. The legend includes a range a numbers with a specific size orange circle associated with each.