floursack vs hopsack

floursack

noun
  • Sackcloth. 

  • A sack for flour. 

hopsack

noun
  • A coarse, loosely-woven clothing fabric. 

  • A hemp sack used for holding hops. 

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