questionableness vs singularity

questionableness

noun
  • The state or condition of being questionable; dubiousness. 

singularity

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

  • 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. 

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