in deep shit vs in it

in deep shit

prep
  • In trouble; up shit creek; in a difficult situation. 

in it

prep
  • In trouble. 

  • Taking part in something, such as a lottery. 

  • Having an expected payout or reward. 

  • Getting on successfully, especially in a game. 

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