presentiment vs reassurance

presentiment

noun
  • A premonition; a feeling that something, often of undesirable nature, is going to happen. 

reassurance

noun
  • The feeling of being reassured, of having confidence restored, of having apprehensions dispelled. 

  • The act of confirming someone's opinion or impression. 

  • Reinsurance. 

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