institution vs sustainment

institution

noun
  • The act of instituting something. 

  • Any long established and respected place or business. 

  • A custom or practice of a society or community. 

  • The building or buildings which house such an organization. 

  • A person long established in a place, position, or field. 

  • A mental institution. 

  • A long established and respected organization, particularly one involved with education, public service, or charity work. 

  • The act by which a bishop commits a cure of souls to a priest. 

sustainment

noun
  • The act of sustaining something. 

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