Added for the sake of completeness. I think the maps showing variations in prevalence across the US, in the paper by Willis et al. (2010), are more useful.
Reference:
[1] "Prevalence of Parkinson’s disease across North America"
C. Marras, J. C. Beck, J. H. Bower, E. Roberts, B Ritz, G. W. Ross, R. D. Abbott, R. Savica, S. K. Van Den Eeden, A. W. Willis & CM Tanner on behalf of the Parkinson’s Foundation P4 Group
npj Parkinson's Disease
volume 4, Article number: 21 (2018)
Prevalence of Parkinson?s disease across North America | npj Parkinson'''s Disease
John