quagmire vs tranquility

quagmire

noun
  • A swampy, soggy area of ground. 

  • A perilous, mixed up and troubled situation; a hopeless tangle. 

verb
  • To embroil (a person, etc.) in complexity or difficulty. 

tranquility

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