go the way of the dodo vs go to pot

go the way of the dodo

verb
  • To go extinct or become obsolete; to fall out of common practice or use; to become a thing of the past. 

go to pot

verb
  • To come to ruin, especially to decline or deteriorate. 

How often have the words go the way of the dodo and go to pot occurred in a corpus of books? (source: Google Ngram Viewer )