jet set vs upper crust

jet set

noun
  • A social class of wealthy people who travel for pleasure. 

verb
  • To follow the life style of the jet set. 

adj
  • Relating to the life style of the jet set. 

upper crust

noun
  • The social elite, the highest social class. 

  • Used other than figuratively or idiomatically: see upper, crust. The topmost layer of a bread, pastry dish, or other item with a hardened coating. 

How often have the words jet set and upper crust occurred in a corpus of books? (source: Google Ngram Viewer )