range graded proportional circle map

A range graded proportional circle map is a proportional circle map where the circles size is dependent on the size of the range it is providing information for.This is a Menard graduated circle map. A Range Graded Proportional Circle Map also map that uses circles based on their size to correlate directly to the quantity for that data given in the symbol key.
http://go.owu.edu/~jbkrygie/krygier_html/geog_353/geog_353_lo/geog_353_lo11.html