boy in blue vs fed

boy in blue

noun
  • A policeman. 

fed

noun
  • A police officer. 

  • A federal government officer or official, especially a FBI, CIA, NSA, ATF, or DEA agent. 

  • A federation in which powerlifters organize to compete. 

  • The Canadian federal government. 

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