survival vs sustention

survival

noun
  • Of, relating to or aiding survival. 

  • The fact or act of surviving; continued existence or life. 

  • The avoidance of relegation or demotion to a lower league or division. 

  • A custom or belief that persists in folklore from earlier times, when the rationale behind it is forgotten. 

sustention

noun
  • sustentation 

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