Add deaths/cases multiplier

[garciaguevara]

Hola!! I am about to do the weekly multipliers (https://www.facebook.com/gapminder.org/posts/3397004387001162) a very simple yet not common metric of evaluation (I have not seen it for Mexico, yet). I will start by states but then do it per metropolitan regions or municipalities. Let me know if you have suggestions or if you think it could be useful to add this in repo.

[AzulGarza]

Hi!

Sounds very useful! It could be a great improvement for Mexico's data.