empty space vs vacancy

empty space

noun
  • Vacuum; a space containing nothing at all 

  • An unoccupied space where something may be stored 

  • A feeling of longing for someone or something that is gone; a sense of a thing's absence. 

  • An unoccupied area or volume. 

vacancy

noun
  • Empty space. 

  • An available room in a hotel; guest house, etc. 

  • An unoccupied position or job. 

  • Lack of intelligence or understanding. 

  • A blank mind, unoccupied with thought. 

  • A defect in a crystal caused by the absence of an atom in a lattice 

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