crack up vs haha

crack up

verb
  • To laugh heartily. 

  • To cause to laugh heartily. 

  • To become insane; to suffer a mental breakdown. 

  • To crash an aircraft or automobile. 

  • To cry up; to extol. 

adj
  • Funny; hilarious 

haha

verb
  • To laugh. 

intj
  • An onomatopoeic representation of laughter. 

noun
  • Type of boundary to a garden, pleasure-ground, or park, designed not to interrupt the view and to be invisible until closely approached. 

  • A large leafy Hawaiian plant, Gunnera petaloidea. 

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