tendency vs unlikelihood

tendency

noun
  • A likelihood of behaving in a particular way or going in a particular direction; a tending toward. 

  • An organised unit or faction within a larger political organisation. 

unlikelihood

noun
  • Absence of likelihood; the state of being unlikely or improbable; improbability. 

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