inertness vs passivity

inertness

noun
  • Lack of activity or exertion; habitual indisposition to action or motion 

  • Absence of the power of self-motion; inertia. 

  • Quality of being unreactive with other chemical compounds or elements. 

passivity

noun
  • The state of being passive. 

  • A lack of initiative. 

  • Submissiveness. 

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