oddity vs wacko

oddity

noun

  • A strange person; an oddball. 

  • Strangeness. 

  • An odd or strange thing or opinion. 

wacko

noun

  • An amusingly eccentric or irrational person. 

adj

  • Amusingly eccentric or irrational. 

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