proprietor vs sitting tenant

proprietor

noun
  • A sole owner of an unincorporated business, also called a sole proprietor. 

  • One of the owners of an unincorporated business, a partner. 

  • One or more persons to whom a colonial territory is assigned, like a fief, including its administration. 

  • An owner. 

sitting tenant

noun
  • A tenant who is already in occupation of a premises, especially when there is a change of owner. The tenant is not evicted when the property is sold to a new owner. 

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