crackup vs splitting

crackup

noun
  • A crash or wreck, generally involving a car or airplane. 

splitting

noun
  • An instance where something splits. 

  • A division in the mind, or affecting one's sense of self. 

  • The cleavage of a covalent bond. 

adj
  • Very rapid. 

  • Resembling the sound of something being split or ripped. 

  • Severely painful. 

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