cowboy boot vs running shoe

cowboy boot

noun
  • A kind of riding boot, historically worn by cowboys, with a high heel traditionally made of stacked leather, a rounded to pointed toe, a high shaft, and often no lacing. 

running shoe

noun
  • One of a pair of running shoes 

How often have the words cowboy boot and running shoe occurred in a corpus of books? (source: Google Ngram Viewer )