nullify vs pull off

nullify

verb
  • To make of no use or value; to cancel out. 

  • To prevent from happening. 

  • To make legally invalid. 

pull off

verb
  • To remove by pulling. 

  • To begin moving and then move away; to pull away. 

  • To masturbate. 

  • To achieve; to succeed at something difficult. 

  • To turn off a road (onto the side of the road, or onto another road). 

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