portent vs winds of change

portent

noun
  • A portending; significance 

  • Something regarded as portentous; a marvel; prodigy. 

  • Something that portends an event about to occur, especially an unfortunate or evil event; an omen. 

winds of change

noun
  • The inexorable process of inevitable societal and political change and progress over time. 

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