freak out vs have one's back up

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. 

have one's back up

verb
  • To be angry or defensive. 

How often have the words freak out and have one's back up occurred in a corpus of books? (source: Google Ngram Viewer )