heterosexuality vs same-sexness

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. 

same-sexness

noun
  • The condition of having or being of the same sex. 

  • Homosexuality. 

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