attend vs knock on wood

attend

verb
  • To turn one's consideration (to); to deal with (a task, problem, concern etc.), to look after. 

  • To be present with; to accompany; to be united or consequent to. 

  • To be present at (an event or place) in order to take part in some action or proceedings; to regularly go to (an event or place). 

  • To wait upon as a servant etc.; to accompany to assist (someone). 

  • To wait for; to await; to remain, abide, or be in store for. 

  • To go to (a place) for some purpose (with at). 

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