agony vs painful experience

agony

noun
  • Extreme pain. 

  • Violent contest or striving. 

  • Paroxysm of joy; keen emotion. 

  • The sufferings of Jesus Christ in the garden of Gethsemane. 

  • The last struggle of life; death struggle. 

painful experience

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