perspicacity vs prior knowledge

perspicacity

noun
  • Acute discernment or understanding; insight. 

  • The human faculty or power to mentally grasp or understand clearly. 

prior knowledge

noun
  • Used other than figuratively or idiomatically: see prior, knowledge. 

  • Knowledge of a set of circumstances sufficient to make actions based on those circumstances wrongful. 

  • Prior to the inception of an insurance policy, knowledge of specific extant circumstances that could reasonably give rise to a claim under that policy. 

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