gayness vs homosexuality

gayness

noun
  • The state of being gay (homosexual); homosexuality. 

homosexuality

noun
  • The state of being sexually attracted primarily or exclusively to persons of the same sex, sometimes (potentially offensive) restricted to same-sex attraction between males. 

  • Sexual activity with a person of the same sex, sometimes (potentially offensive) restricted to same-sex sex between males. 

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