ottoman vs sofa bed

ottoman

noun
  • An upholstered sofa, without arms or a back, sometimes with a compartment for storing linen etc. 

  • A low stool or thick cushion used to rest the feet or as a seat. 

  • A fabric with a pronounced ribbed or corded effect, often made of silk or a mixture of cotton and silk-like yarns. 

sofa bed

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