oof vs tremble

oof

noun
  • A sound made in pain, as when expelling air after being struck. 

intj
  • A sound mimicking the loss of air, as if someone's solar plexus had just been struck. 

  • Synonym of ouch (“expressing sympathy at another's pain, shock at a high price, etc.”) 

tremble

noun
  • A shake, quiver, or vibration. 

verb
  • To shake, quiver, or vibrate. 

  • To fear; to be afraid. 

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