blandness vs ennui

blandness

noun
  • The state, quality, or characteristic of being bland. 

ennui

noun
  • A gripping listlessness or melancholia caused by boredom; depression. 

verb
  • To make bored or listless; to weary. 

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