[solve]

Shows percent change... but not the magnitude of the change.

Seeing a map that combined both percentage and magnitude to compute the colors (perhaps similar to the Tf–idf calculation?) would be much more interpretable. 50% of people leaving the middle of a forest doesn't really tell me much, versus 50% change in a dense city.

[zzleeper]

True.. I see the big blue shades between Portugal and Spain and imagine those areas growing, but that region is basically rural