ethnic cleansing vs execution

ethnic cleansing

noun
  • The mass expulsion or killing of people belonging to one ethnic group by those of another. 

execution

noun
  • The act of putting to death or being put to death as a penalty, or actions so associated. 

  • The carrying out of an instruction, program or program segment by a computer. 

  • The act, manner or style of executing (actions, maneuvers, performances). 

  • The carrying into effect of a court judgment, or of a will. 

  • The formal process by which a contract is made valid and put into binding effect. 

  • The state of being accomplished. 

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