preemption vs prevention

preemption

noun
  • The temporary interruption of a task without its cooperation and with the intention of resuming it at a later time. 

  • The purchase of something before it is offered for sale to others. 

  • The displacement of a lower jurisdiction's laws when they conflict with those of a higher jurisdiction. 

  • The purchase of public land by the occupant. 

prevention

noun
  • The act of preventing or hindering; obstruction of action, access, or approach; thwarting. 

  • precaution; forethought. 

  • Any measure intended to limit health-related risks (such as information campaigns, vaccination, early diagnosis etc.). 

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