bombardment vs bombing

bombardment

noun
  • the act of bombing, especially towns or cities 

  • heavy artillery fire 

  • the incidence of an intense stream of high-energy particles directed at a substance 

bombing

noun
  • The action of placing and detonating bombs. 

  • The action of dropping bombs from the air. 

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