adverse possession vs authorization

adverse possession

noun
  • A means of acquiring title to another's real property without compensation by occupying the property in a manner that has under common law the requirements of being actual, open and notorious, exclusive, hostile, under cover of claim or right, and continuous for a certain number of years. 

authorization

noun
  • (A document giving) formal sanction, permission or warrant. 

  • Permission. 

  • Permission, possibly limited, to spend funds for a specific budgetary purpose. 

  • An act of authorizing. 

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