plummeting vs prolapse

plummeting

noun
  • A violent or dramatic fall. 

prolapse

noun
  • A moving out of place, especially a protrusion of an internal organ 

verb
  • To move out of place; especially for an internal organ to protrude beyond its normal position. 

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