taco vs wetback

taco

noun
  • A Mexican snack food made of a small tortilla (soft or hard shelled) filled with ingredients such as meat, rice, beans, cheese, diced vegetables and salsa. 

  • The vulva. 

  • A yellow stain on a shirt armpit caused by sweat or deodorant. 

verb
  • To fold or cause to buckle in half, similar to the way a taco is folded. 

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 taco and wetback occurred in a corpus of books? (source: Google Ngram Viewer )