express train vs whistle-stop

express train

noun
  • A train (either the service or the train itself) making limited stops. 

whistle-stop

noun
  • A small train station. 

  • A brief stop on a campaign tour to make a speech or perform some other type of public electioneering. 

verb
  • To make a brief stop on a campaign tour to make a speech or perform some other type of public electioneering. 

adj
  • Extremely brief and hurried. 

How often have the words express train and whistle-stop occurred in a corpus of books? (source: Google Ngram Viewer )