homosexuality vs leaning

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. 

leaning

noun
  • A tendency or propensity. 

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