quay vs staithe

quay

noun
  • A stone or concrete structure on navigable water used for loading and unloading vessels; a wharf. 

verb
  • To land or tie up at a quay or similar structure, especially used in the phrase "quay up". 

staithe

noun
  • An installation built at the railside or nearby for the storage of coal unloaded from wagons. 

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