biosphere vs occupancy

biosphere

noun
  • The totality of living organisms and their environment. 

  • The part of the Earth and its atmosphere capable of supporting life. 

occupancy

noun
  • The act of occupying, the state of being occupied or the state of being an occupant or tenant. 

  • The specific use to which something occupied is put. 

  • The period of time during which someone rents or otherwise occupies certain land or premises. 

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