dullness vs lack of interest

dullness

noun

  • 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. 

  • Lack of interest or excitement. 

  • The lack of visual brilliance; want of sheen. 

  • bluntness. 

lack of interest

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