backbreaking vs crushing

backbreaking

adj
  • Of work, very physically tiring. 

crushing

adj
  • Devastatingly disheartening. 

  • That crushes; overwhelming. 

noun
  • The act of subjecting sugarcane to crushing. 

  • The action of the verb to crush. 

  • Crushed material. 

  • A former method of execution by placing heavy weights on the victim. 

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