X-rated vs close to the bone

X-rated

adj
  • Denoting a film given an X classification. 

  • Pornographic or indecent. 

close to the bone

adj
  • Destitute. 

  • Penetrating and relatable, to the point of causing discomfort. 

How often have the words X-rated and close to the bone occurred in a corpus of books? (source: Google Ngram Viewer )