dehydration vs evanescence

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. 

evanescence

noun
  • The act or state of vanishing away; disappearance. 

  • The event of fading and gradually vanishing from sight. 

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