appeasement vs quelling

appeasement

noun
  • The state of being appeased; the policy of giving in to demands in order to preserve the peace. 

quelling

noun
  • The act by which something is quelled. 

adj
  • causing something to quell or be quelled 

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