hope vs knock on wood

hope

verb
  • To want something to happen, with a sense of expectation that it might. 

  • To wish. 

  • To place confidence; to trust with confident expectation of good; usually followed by in. 

  • To be optimistic; be full of hope; have hopes. 

noun
  • A sloping plain between mountain ridges. 

  • A small bay; an inlet; a haven. 

  • A hollow; a valley, especially the upper end of a narrow mountain valley when it is nearly encircled by smooth, green slopes; a combe. 

  • The virtuous desire for future good. 

  • The feeling of trust, confidence, belief or expectation that something wished for can or will happen. 

  • The actual thing wished for. 

  • A person or thing that is a source of hope. 

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 hope and knock on wood occurred in a corpus of books? (source: Google Ngram Viewer )