megadeath vs pogrom

megadeath

noun
  • One million deaths, especially as a unit of measure in reference to nuclear warfare. 

pogrom

noun
  • An antisemitic hate crime with a large death toll, irrespective of the number of perpetrators. 

  • A riot aimed at persecution or massacre of a particular ethnic or religious group, usually Jews. 

verb
  • To persecute or massacre a particular group of people. 

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