sommelier vs waiter

sommelier

noun
  • The member of staff at a restaurant who keeps the wine cellar and advises the guests on a choice of wines; a wine steward / stewardess, a wine waiter / waitress / server. 

verb
  • To act as a sommelier. 

waiter

noun
  • A male or female attendant who serves customers at their tables in a restaurant, café or similar. 

  • A person working as an attendant at the London Stock Exchange. 

  • Someone who waits for somebody or something; a person who is waiting. 

verb
  • To work as a waiter. 

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