greaser vs wetback

greaser

noun
  • A Latin American, especially a Mexican. 

  • A mechanic. 

  • Someone or something that greases (applies grease). 

  • A biker, a tough. 

  • A rocker or metalhead, especially one who listens to 1950s rock and roll or 1980s thrash metal. 

  • An Italian. 

  • A Greek. 

wetback

noun
  • A Mexican or Central American who illegally enters the United States of America from its southern border. 

  • A person of the mestizo race; a mojado. 

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