litigate vs pin on

litigate

verb
  • To dispute; to fight over. 

  • To go to law; to carry on a lawsuit. 

  • To contest in law. 

pin on

verb
  • To place the blame for (something) on (someone), especially unjustly. 

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