affray vs pig pile

affray

noun
  • The fighting of two or more persons, in a public place, to the terror of others. 

  • The act of suddenly disturbing anyone; an assault or attack. 

  • A tumultuous assault or quarrel. 

pig pile

noun
  • A disorderly pile of people formed by jumping upon a victim. 

verb
  • To jump into such a pile. 

  • To cause a group of people to lie in a pile upon another, originally as a punishment to the victim on the bottom. 

  • To act similarly with regard to residential density: to live or cause to live in high-density settlements. 

How often have the words affray and pig pile occurred in a corpus of books? (source: Google Ngram Viewer )