aggravate vs fan the flames

aggravate

verb
  • To make worse; to exacerbate. 

  • To exasperate; to provoke or irritate. 

  • To make (an offence) worse or more severe; to increase in offensiveness or heinousness. 

fan the flames

verb
  • To intensify or worsen an already difficult situation. 

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