MDMA vs empathy

MDMA

noun
  • 3,4-methylenedioxymethamphetamine, a synthetic entactogen of the methylenedioxyphenethylamine family. 

empathy

noun
  • Capacity to understand another person's point of view or the result of such understanding. 

  • Identification with or understanding of the thoughts, feelings, or emotional state of another person. 

  • A paranormal ability to psychically read another person's emotions. 

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