enervation vs passivity

enervation

noun
  • State of being enervated; debility. 

  • Act of enervating; debilitation. 

passivity

noun
  • The state of being passive. 

  • A lack of initiative. 

  • Submissiveness. 

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