pannier vs shopping bag

pannier

noun
  • A large basket or bag fastened, usually in pairs, to the back of a bicycle or pack animal, or carried in pairs over the shoulders. 

  • One of a pair of hoops used to expand the volume of a woman's skirt to either side. 

  • A breadbasket. 

  • A piece of basketwork for protecting archers, or, filled with gravel or sand, for forming and protecting embankments, etc. 

  • A decorative basket for the display of flowers or fruits. 

shopping bag

noun
  • A strong bag with handles used to put purchases in; usually made of plastic, paper or fabric, sometimes given away with a purchase. 

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