dullness vs passivity

dullness

noun
  • Lack of interest or excitement. 

  • The quality of not perceiving or kenning things distinctly. 

  • The quality of being uninteresting; boring; humorless or irksome. 

  • The quality of being slow of understanding things; stupidity. 

  • The lack of visual brilliance; want of sheen. 

  • bluntness. 

passivity

noun
  • A lack of initiative. 

  • The state of being passive. 

  • Submissiveness. 

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