demesne vs ecosphere

demesne

noun
  • A region or area; a domain. 

  • A lord's chief manor place, with that part of the lands belonging thereto which has not been granted out in tenancy; a house, and the land adjoining, kept for the proprietor's own use. 

ecosphere

noun
  • the biosphere 

  • The portion of the atmosphere from sea-level to about 4000 meters in which it is possible to breathe without technological assistance. 

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