uninhabitable vs usable

uninhabitable

adj
  • Not fit for people (or other living things) to live in; not able to be inhabited. 

usable

adj
  • Easy to use; exhibiting good usability. 

  • homosexual 

  • Capable of being used. 

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