Bloody Mary vs menstruation

Bloody Mary

name
  • A ghost, witch or demonic spirit said to appear in a mirror if her name is chanted repeatedly. 

  • Mary I of England 

menstruation

noun
  • An instance of menstruation, the part of each month during which a fertile woman menstruates. 

  • The periodic discharging of the menses, the flow of blood and cells from the lining of the uterus in unfertilized females of humans and other primates. 

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