heterosexuality vs heterosexualness

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. 

heterosexualness

noun
  • The quality of being heterosexual. 

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