penetrable vs porous

penetrable

adj
  • Capable of being penetrated, entered, or pierced. Also figuratively. 

porous

adj
  • full of loopholes 

  • Full of tiny pores that allow fluids or gasses to pass through. 

  • With many gaps. 

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