heterosexuality vs sapphism

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. 

sapphism

noun
  • Lesbianism; female homosexuality. 

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