cramped vs imperviable

cramped

adj
  • Illegible. 

  • Overcrowded or congested. 

  • Tight because of or like suffering a cramp. 

  • Uncomfortably restricted in size or space, or financially. 

imperviable

adj
  • impervious 

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