mistreatment vs sexual abuse

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 abuse

noun
  • Any sexual activity that is undesired by one participant but forced on them nonetheless, especially when considered to be more sustained or frequent than an incident of sexual assault. 

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