inflexibility vs pusillanimity

inflexibility

noun
  • The quality or state of being inflexible, or not capable of being bent or changed; unyielding stiffness 

pusillanimity

noun
  • The quality or state of being pusillanimous; the vice of being timid and cowardly, and thus not living up to one's full potential; pusillanimousness. 

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