clear-out vs depopulation

clear-out

noun
  • The act of emptying a room or space. 

  • A semicircular sweep with the ball grasped firmly in both hands. 

depopulation

noun
  • The act of depopulating or condition of being depopulated; the destruction or expulsion of inhabitants. 

How often have the words clear-out and depopulation occurred in a corpus of books? (source: Google Ngram Viewer )