BOB vs vagina

BOB

noun
  • Vibrator (device designed to stimulate a woman's genitals). 

adj
  • Back-of-the-book; denoting those stamps in a catalogue that are not used for the payment of regular postage fees, and are displayed separately in the catalogue after that listing; the division between these two groups varies with the publisher. 

vagina

noun
  • The passage leading from the opening of the vulva to the cervix of the uterus for copulation and childbirth in female mammals. 

  • The vulva, or the vulva and the vaginal passage collectively. 

  • A similar part in some invertebrates. 

  • A sheathlike structure, such as the leaf of a grass that surrounds a stem. 

  • A coward; a weakling; a pussy. 

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