oddity vs singularity

oddity

noun
  • An odd or strange thing or opinion. 

  • Strangeness. 

  • A strange person; an oddball. 

singularity

noun
  • An unusual action or behaviour. 

  • A point where all parallel lines meet. 

  • Celibacy, singleness (as contrasted with marriage). 

  • A point where a measured variable reaches unmeasurable or infinite value. 

  • The value or range of values of a function for which a derivative does not exist. 

  • The state of being singular, distinct, peculiar, uncommon or unusual. 

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