subsistence vs sustention

subsistence

noun
  • Inherency. 

  • Embodiment or personification or hypostasis of an underlying principle or quality. 

  • Real being; existence. 

  • Something (food, water, money, etc.) that is required to stay alive. 

  • The act of maintaining oneself at a minimum level. 

sustention

noun
  • sustentation 

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