hard candy vs toffee

hard candy

noun
  • A candy prepared from one or more syrups boiled to a temperature of 160°C (320°F), thereafter becoming stiff and brittle at room temperature. 

toffee

noun
  • A type of confectionery made by boiling sugar (or treacle, etc) with butter or milk, then cooling the mixture so that it becomes hard. 

  • A small, individual piece of toffee. 

  • Any kind of sweets; candy. 

verb
  • To coat in toffee. 

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