Mary Joanna vs herb

Mary Joanna

noun
  • Marijuana; cannabis. 

herb

noun
  • Cannabis. 

  • A lame or uncool person. 

  • Any green, leafy plant, or parts thereof, used to flavour or season food. 

  • A plant whose stem is not woody and does not persist beyond each growing season 

  • A plant whose roots, leaves or seeds, etc. are used in medicine. 

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