/ xkcd

choropleth

I love this. Such a better way of showing distributions.
https://xkcd.com/1939/

p.s. From my computer's dictionary:

choropleth map | ˈkôrəˌpleTH ˌmap |
noun
  a map that uses differences in shading, coloring, or the
  placing of symbols within predefined areas to indicate the
  average values of a property or quantity in those areas.
  Compare with isopleth.

ORIGIN
1930s: choropleth from Greek khōra ‘region’ + plēthos ‘multitude’.