Cocker vs Irk

Cocker

name
  • A short river in Lancashire, England, which flows into the Lune estuary. 

  • A river in Cumbria, England, which joins the Derwent at Cockermouth. 

  • A surname. 

Irk

name
  • A river in Greater Manchester, England, which joins the River Irwell in Manchester city centre. 

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