

Some links for related information :


This is an interesting map because it gives the exact value next to the proportional symbol representation. I think that even though the exact values are shown, a key that said blue is increase and red is decrease in net population would be helpful. Also, an inset showing where this region lies on the state of New York would be a nice addition as well.
Here is a choropleth map of Missouri that shows the percent of the total state economy that each county accounts for. The colors are very distinct and it is easy to see where the bulk of the economic activity takes place.