industrial action vs sleep-in

industrial action

noun
  • A workplace protest by employees designed to inconvenience or disrupt the business of the employer. 

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 industrial action and sleep-in occurred in a corpus of books? (source: Google Ngram Viewer )