break down vs fracture

break down

verb
  • To collapse, physically or in structure. (unexpectedly) 

  • To demolish, to pull down. (intentionally) 

  • To divide into parts to give more details, to provide a more indepth analysis of. 

  • To (cause to) decay, to decompose. 

  • To cease to function. (others) 

  • To stop functioning. (machine, computer, vehicle) 

  • To fail, especially socially or for political reasons. 

  • To give in, relent, concede, or surrender. 

  • To render or to become weak and ineffective. 

  • To digest. 

  • To render or to become unstable due to stress, to collapse physically or mentally. 

fracture

verb
  • To break, or cause something to break. 

  • To amuse (a person) greatly; to split someone's sides. 

noun
  • A break in bone or cartilage. 

  • An instance of breaking, a place where something has broken. 

  • A fault or crack in a rock. 

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