hogshead vs solera

hogshead

noun
  • An English measure of capacity for liquids, containing 63 wine gallons, or about 52+¹⁄₂ imperial gallons; a half pipe. 

  • A large barrel or cask of indefinite contents, especially one containing from 100 to 140 gallons. 

solera

noun
  • A large wine cask, on the bottom tier in this system, that contains the oldest wine 

  • A method of producing sherry in which small amounts of younger wines stored in an upper tier of casks are systematically blended with the more mature wine in the casks below 

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