fleeable vs impossible

fleeable

adj
  • Able to be fled from; escapable. 

impossible

adj
  • Not possible; not able to be done or happen. 

  • Very difficult to deal with. 

noun
  • A skateboard trick consisting of a backflip performed in midair. 

  • An impossibility. 

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