dehydration vs evaporation

dehydration

noun
  • The act or process of removing water from something. 

  • The condition in which water in the body drops below normal levels, usually caused by illness, sweating or by not drinking enough. 

evaporation

noun
  • The process of a liquid converting to the gaseous state. 

  • The process in which all or a portion of liquid (in a container) is turned into vapour, in order to increase the concentration of solid matter in the mixture. 

How often have the words dehydration and evaporation occurred in a corpus of books? (source: Google Ngram Viewer )