Cargo vs Slough

Cargo

name
  • A village in Kingmoor parish, Carlisle, Cumbria, England (OS grid ref NY3659). 

  • A surname. 

Slough

name
  • A town in east Berkshire, England (formerly Buckinghamshire), close to Heathrow Airport. 

  • A borough and unitary authority (Slough Borough Council) in Berkshire. 

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