pourboire vs premium

pourboire

noun
  • A bribe. 

  • A tip (extra money given to e.g. a waiter in appreciation of service), especially in French contexts. 

premium

noun
  • A prize or award. 

  • A bonus paid in addition to normal payments. 

  • The amount to be paid for an insurance policy. 

  • Something offered at a reduced price as an inducement to buy something else. 

  • An unusually high value. 

  • The amount by which a security's value exceeds its face value. 

adj
  • High-end; belonging to the market segment between mid-market and luxury. 

  • Superior in quality; higher in price or value. 

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