lingua franca vs pidgin English

lingua franca

noun
  • A common language used by people of diverse backgrounds to communicate with one another, often a basic form of speech with simplified grammar, particularly, one not the first language of any of its speakers. 

pidgin English

noun
  • Any very basic English; broken English. 

  • Any English-lexifier pidgin. 

  • The Chinese pidgin English spoken in Canton and Hong Kong, later spreading throughout the Chinese and Southeast Asian coastal region. 

How often have the words lingua franca and pidgin English occurred in a corpus of books? (source: Google Ngram Viewer )