hiatus vs moratorium

hiatus

noun
  • An interruption, break or pause. 

  • A gap in a series, making it incomplete. 

  • An opening in an organ. 

  • A gap in geological strata. 

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

  • An unexpected break from work. 

moratorium

noun
  • A suspension of an ongoing activity. 

  • An authorization to a debtor, permitting temporary suspension of payments. 

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