petting vs sex crime

petting

noun
  • The act of kissing, stroking, etc., a person in a sexual manner. 

  • The act of stroking or gently patting an animal. 

  • The act of indulging or treating as a favourite. 

sex crime

noun
  • An unlawful sexual act. 

How often have the words petting and sex crime occurred in a corpus of books? (source: Google Ngram Viewer )