blue heeler vs cordwainer

blue heeler

noun
  • A police officer. 

  • A blue-coated variety of the Australian Cattle Dog breed. 

cordwainer

noun
  • A worker in cordwain. 

  • A member of the Worshipful Company of Cordwainers, a livery company. 

  • A shoemaker. 

  • A leather from Córdoba. 

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