cat's pyjamas vs cat's whiskers

cat's pyjamas

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

cat's whiskers

noun
  • Something considered to be outstanding. 

  • Java tea (Orthosiphon aristatus) 

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