precede vs usher in

precede

verb
  • To cause to be preceded; to preface; to introduce. 

  • To have higher rank than (someone or something else). 

  • To go before, go in front of. 

noun
  • Brief editorial preface (usually to an article or essay) 

usher in

verb
  • To begin something with preparatory material; to introduce. 

  • To announce the arrival of something; to herald. 

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