anorak vs oilskin

anorak

noun
  • A heavy weatherproof jacket with an attached hood; a parka or windcheater. 

  • A person with an unusual or obsessive interest in a niche subject. 

oilskin

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

  • Cloth made from cotton and 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 anorak and oilskin occurred in a corpus of books? (source: Google Ngram Viewer )