fashionable vs the in thing

fashionable

adj
  • Characteristic of or influenced by a current popular trend or style. 

  • Established or favoured by custom or use; current; prevailing at a particular time. 

noun
  • A fashionable person; a fop. 

the in thing

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