mistreatment vs sexual assault

mistreatment

noun
  • Cruel, abusive , bad, unfair, or thoughtless treatment of a person or animal (only rarely of an object or a machine; usually: mishandle). 

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 mistreatment and sexual assault occurred in a corpus of books? (source: Google Ngram Viewer )