impugn vs tear someone a new one

impugn

verb
  • To verbally assault, especially to argue against an opinion, motive, or action; to question the truth or validity of. 

tear someone a new one

verb
  • To express great anger toward (a person) for some perceived offence or shortcoming; to castigate. 

How often have the words impugn and tear someone a new one occurred in a corpus of books? (source: Google Ngram Viewer )