blot out vs keep out of sight

blot out

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

  • To obscure. 

  • To annihilate 

  • To make indecipherable; to obliterate. 

keep out of sight

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