coitus interruptus vs debouchment

coitus interruptus

noun
  • Sexual intercourse interrupted by withdrawal of the penis before ejaculation. 

debouchment

noun
  • The act, or the result of debouching 

  • The point of debouch of a watercourse 

  • Opening or emptying into another part 

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