knock on wood vs look at sunny side

knock on wood

verb
  • To take a customary action to ward off some misfortune that is believed to be attracted by a presumptuous statement. 

intj
  • Hopefully; a self-directive to undertake the customary action to ward off bad luck. 

look at sunny side

How often have the words knock on wood and look at sunny side occurred in a corpus of books? (source: Google Ngram Viewer )