R-rated vs mature

R-rated

adj
  • Of a motion picture, having an "R rating" from one more motion picture rating authorities, typically meaning it is suitable only for adults. 

  • Not suitable for children, especially due to involving excessive sexual, violent, or rude content 

  • Of a motion picture, having an "R rating" from the Motion Picture Association (MPA), meaning it is suitable only for adults. 

mature

adj
  • Brought to a state of complete readiness. 

  • Profound; careful. 

  • Fully developed; grown up in terms of physical appearance, behaviour or thinking; ripe. 

  • Suitable for adults only, due to sexual themes, violence, etc. 

verb
  • To attain maturity, to become mature or ripe. 

  • To make (something, e.g. fruit) ripe or mature. 

  • To make (someone) mature. 

  • To proceed toward maturity: full development or completion (either of concrete or of abstract things, e.g. plans, judgments, qualities). 

  • To proceed toward or become mature or full-grown, either physically or psychologically; to gain experience or wisdom with age. 

  • To bring (something) to maturity, full development, or completion. 

  • To reach the date when payment is due. 

How often have the words R-rated and mature occurred in a corpus of books? (source: Google Ngram Viewer )