giggle vs haha

giggle

verb
  • To laugh gently in a playful, nervous, or affected manner. 

noun
  • Fun; an amusing episode. 

  • A high-pitched, silly laugh. 

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 giggle and haha occurred in a corpus of books? (source: Google Ngram Viewer )