freak out vs shit oneself

freak out

verb
  • To scare or unnerve someone. 

  • To react with extreme anger or fear, to the extent that one loses one's composure or behaves irrationally. 

shit oneself

verb
  • To be very frightened or astonished (to the extent that one might lose control of one's bowels). 

  • To soil oneself. 

How often have the words freak out and shit oneself occurred in a corpus of books? (source: Google Ngram Viewer )