butt-fucking vs tradesman's entrance

butt-fucking

noun

  • anal sex 

adj

  • Engaging in anal sex 

tradesman's entrance

noun

  • The anus. 

  • The entrance to a large house, used by tradesmen to deliver goods and services; usually at the side or rear. 

How often have the words butt-fucking and tradesman's entrance occurred in a corpus of books? (source: Google Ngram Viewer )