anger vs flare up

anger

verb
  • To become angry. 

  • To cause such a feeling of antagonism in. 

noun
  • A strong feeling of displeasure, hostility or antagonism towards someone or something, usually combined with an urge to harm, often stemming from perceived provocation, hurt, or threat. 

flare up

verb
  • To burst out suddenly, as in anger. 

  • To become more intense suddenly. 

  • To burn brightly again. 

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