derringer vs forty-five

derringer

noun
  • A type of very small, concealable pistol with one or two barrels, but without any loading system or magazine. 

forty-five

noun
  • A .45-caliber firearm. 

num
  • Cardinal number after forty-four and before forty-six. 

How often have the words derringer and forty-five occurred in a corpus of books? (source: Google Ngram Viewer )