emigrant vs guest worker

emigrant

noun
  • Someone who leaves a country to settle in a new country. 

  • Any of various pierid butterflies of the genus Catopsilia. Also called a migrant. 

guest worker

noun
  • A person with temporary permission to work in another country. 

How often have the words emigrant and guest worker occurred in a corpus of books? (source: Google Ngram Viewer )