gender identity vs heterosexuality

gender identity

noun
  • A person's internal sense of self as belonging to a particular gender or genders, or to no gender. 

heterosexuality

noun
  • The state of being sexually and romantically attracted primarily or exclusively to persons of the opposite sex. 

  • Sexual activity with a person of the opposite sex. 

How often have the words gender identity and heterosexuality occurred in a corpus of books? (source: Google Ngram Viewer )