industrial action vs write-in

industrial action

noun

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

write-in

adj

  • Pertaining to a write-in. 

noun

  • A candidate whose name is not listed on the ballot. 

  • A vote made for a candidate of this kind. 

How often have the words industrial action and write-in occurred in a corpus of books? (source: Google Ngram Viewer )