outlet vs retail outlet

outlet

noun
  • A vent or similar passage to allow the escape of something. 

  • A river that runs out of a lake. 

  • Something which allows for the release of one's desires. 

  • A shop that sells the products of a particular manufacturer or supplier. 

  • A wall-mounted device such as a socket or receptacle connected to an electrical system at which current is taken to supply utilization equipment or appliances. 

retail outlet

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