mac vs oilskin

mac

oilskin

noun
  • Cloth made from cotton and treated with oil and pigment to make it waterproof. 

  • A raincoat made from cotton fabric treated with oil and pigment to make it waterproof. 

  • Foul-weather gear worn by sailors, whether of natural or synthetic materials. 

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