dirty protest vs sleep-in

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. 

sleep-in

noun
  • An instance of sleeping in, sleeping late, sleeping until one feels fully refreshed rather than rising at a prespecified time. 

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