Mexican peso vs peso

Mexican peso

peso

noun
  • The circulating currency of various Spanish-speaking American countries (Argentina, Chile, Colombia, Cuba, the Dominican Republic, Mexico, and Uruguay) and the Philippines. 

  • A former unit of currency in Spain and Spain's colonies, worth 8 reales; the Spanish dollar. 

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