acquaintance rape vs sexual assault

acquaintance rape

noun
  • Rape by someone known to the victim, such as date rape, marital rape, or rape by a teacher or supervisor. 

sexual assault

noun
  • A physical attack of a sexual nature on another person or a sexual act committed without explicit consent. 

How often have the words acquaintance rape and sexual assault occurred in a corpus of books? (source: Google Ngram Viewer )