sustenance vs viaticum

sustenance

noun
  • Something that provides support or nourishment. 

viaticum

noun
  • Provisions, money, or other supplies given to someone setting off on a long journey. 

  • The Eucharist, when given to a person who is dying or one in danger of death. 

  • A portable altar. 

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