alleyway vs back street

alleyway

noun
  • A narrow street formed by the proximity of adjacent buildings. 

  • A passage between two rows of cabins in a ship. 

back street

noun
  • A usually small and narrow street or alley, especially one in inferior or poorer parts of a city, away from the centre. 

  • A secret, clandestine or illegal scene. 

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