criminal conversation vs statutory rape

criminal conversation

noun
  • Unlawful sexual intercourse with a married person; adultery; a common law tort arising from adultery, abolished in many jurisdictions. 

statutory rape

noun
  • An illegal act of sexual intercourse by an adult with a person under the legal age of consent for sex, or with another adult who is not able to consent because of intellectual disability. 

How often have the words criminal conversation and statutory rape occurred in a corpus of books? (source: Google Ngram Viewer )