learned vs straight from horse’s mouth

learned

adj
  • Derived from experience; acquired by learning. 

  • Having much learning, knowledgeable, erudite; highly educated. 

  • Scholarly, exhibiting scholarship. 

  • A courteous description used in various ways to refer to lawyers or judges. 

straight from horse’s mouth

How often have the words learned and straight from horse’s mouth occurred in a corpus of books? (source: Google Ngram Viewer )