vacuity vs vacuousness

vacuity

noun
  • Idleness; listlessness. 

  • Emptiness. 

  • Physical emptiness, an absence of matter; vacuum. 

  • An empty or inane remark or thing. 

vacuousness

noun
  • the quality of being vacuous 

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