dirty protest vs gherao

dirty protest

noun
  • A form of protest where a prisoner refuses to use the toilet and instead defecates and urinates within his or her cell. 

gherao

noun
  • A protest in which a group of people surrounds a politician, building, etc. until demands are met. 

verb
  • To surround for this purpose. 

How often have the words dirty protest and gherao occurred in a corpus of books? (source: Google Ngram Viewer )