cave-in vs disintegration

cave-in

disintegration

noun
  • The wearing away or falling to pieces of rocks or strata, produced by atmospheric action, frost, ice, etc. 

  • The process of radioactive decay. 

  • The condition of anything which has disintegrated. 

  • The radioactive decay of a single atom. 

  • A process by which anything disintegrates. 

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