go under vs suffocate in water

go under

verb
  • To enter a trance, state of hypnosis, etc. 

  • To be named; to call oneself. 

  • To collapse or fail, e.g. by going bankrupt. 

  • To descend into a body of water; to founder. 

suffocate in water

How often have the words go under and suffocate in water occurred in a corpus of books? (source: Google Ngram Viewer )