inform on vs turn in

inform on

verb
  • To tell on someone; to act as an informant against. 

turn in

verb
  • To relinquish; give up; to tell on someone to the authorities (especially to turn someone in). 

  • To convert a goal using a turning motion of the body. 

  • To submit something; to give. 

  • To go to bed; to retire to bed. 

  • To reverse the ends of threads and insert them back into the piece being woven so they do not protrude and eventually unravel. 

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