Map Blog Post #10 Bivariate

 I think this is a very interesting Bivariate map. Proportional symbol and dot density are not commonly combined. Also the dots are separated into two categories and different colors and shapes. Does this then make it a trivariate map? I am assuming it is an older map because it is making an estimate of what the population will be in the 1970 census. I do not think the dots should be colored red with the orange proportional symbols because it blobs a bit. I would have used blue or green for contrast.