accept vs knock on wood

accept

verb
  • To regard as proper, usual, true, or to believe in. 

  • To admit to a place or a group. 

  • To acknowledge patiently without opposition or resistance. 

  • To endure patiently. 

  • To receive, especially with a consent, with favour, or with approval. 

  • To agree to pay. 

  • To receive officially. 

  • To receive as adequate or satisfactory. 

  • To receive or admit to; to agree to; to assent to; to submit to. 

  • To receive something willingly. 

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. 

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