Doc Martens vs balmoral

Doc Martens

noun
  • Dr. Martens-brand footwear, especially a style of high lace-up leather boot with air-cushioned sole, traditionally associated with British skinheads, adopted by other subcultures at various times. 

balmoral

noun
  • A Scottish cap with a flat top and a plume but no brim; a blue bonnet. 

  • A heavy walking shoe. 

  • A figured woollen petticoat. 

  • An Oxford shoe. 

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