lassitude vs suspended animation

lassitude

noun
  • Lethargy or lack of energy; fatigue. 

  • Listlessness or languor. 

suspended animation

noun
  • A temporary cessation of breathing and consciousness resembling death; often the result of asphyxia. 

  • The deliberate slowing of the body's functions, sometimes by the use of cryonics, on long interstellar journeys. 

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