unbeing vs vacuity

unbeing

noun
  • Nonexistence. 

  • A nonbeing; an entity of no existence or significance. 

vacuity

noun
  • Emptiness. 

  • Idleness; listlessness. 

  • Physical emptiness, an absence of matter; vacuum. 

  • An empty or inane remark or thing. 

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