blot out vs expunge

blot out

verb
  • To annihilate 

  • Used other than figuratively or idiomatically: see blot, out. 

  • To obscure. 

  • To make indecipherable; to obliterate. 

expunge

verb
  • To eliminate completely; to annihilate. 

  • To delete permanently (e-mail etc.) that was previously marked for deletion but still stored. 

  • To erase or strike out. 

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