Rolls-Royce vs cat's pyjamas

Rolls-Royce

noun
  • A car made by this manufacturer. 

  • Anything that is the best of its type; the best quality product possible. 

name
  • any of several British companies that make motor cars, aero engines, etc. 

cat's pyjamas

noun
  • A highly sought-after and fancy example of something, usually referring to inanimate objects. 

How often have the words Rolls-Royce and cat's pyjamas occurred in a corpus of books? (source: Google Ngram Viewer )