nip in the bud vs ward off

nip in the bud

verb
  • To stop (something) at an early stage. 

  • To remove a bud [from a plant] to prevent flower and fruit from forming. 

ward off

verb
  • To avert or prevent. 

  • To parry, or turn aside. 

How often have the words nip in the bud and ward off occurred in a corpus of books? (source: Google Ngram Viewer )