avert vs hold off

avert

verb
  • To ward off, or prevent, the occurrence or effects of. 

  • To turn aside or away. 

hold off

verb
  • To delay someone or something temporarily; to keep at bay. 

  • To delay commencing (an action until some specified time or event has passed). 

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