empty space vs hiatus

empty space

noun
  • An unoccupied space where something may be stored 

  • Vacuum; a space containing nothing at all 

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

  • An unoccupied area or volume. 

hiatus

noun
  • An opening in an organ. 

  • A gap in a series, making it incomplete. 

  • A gap in geological strata. 

  • A syllable break between two vowels, without an intervening consonant. (Compare diphthong.) 

  • An unexpected break from work. 

  • An interruption, break or pause. 

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