distraction vs knotty question

distraction

noun
  • The process of being distracted. 

  • Perturbation; disorder; disturbance; confusion. 

  • Something that distracts. 

  • Mental disarray; a deranged state of mind; insanity. 

knotty question

How often have the words distraction and knotty question occurred in a corpus of books? (source: Google Ngram Viewer )