preservation vs trusteeship

preservation

noun
  • The act of preserving; care to preserve; act of keeping from destruction, decay or any ill. 

  • The state of being preserved, how something has survived. 

trusteeship

noun
  • Office or function of a trustee. 

  • The administrative control of a territory granted to a country by the Trusteeship Council of the United Nations. 

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