prebuttal vs preemption

prebuttal

noun
  • A preemptive rebuttal. 

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. 

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