bast vs sisal

bast

noun
  • Fibre made from the phloem of certain plants and used for matting and cord. 

sisal

noun
  • The fibre of the plant. 

  • A sisal mat. 

  • A Central American plant, Agave sisalana, cultivated for its sword-shaped leaves that yield fibers used for rope. 

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