British English vs North American English

British English

noun
  • The English language as written and spoken in the United Kingdom (in contrast with other places, particularly other countries where English is predominant or at least an important language) 

adj
  • Of or relating to, or spoken or written in British English. 

North American English

name
  • The variety of the English language used in the United States of America and Canada. 

How often have the words British English and North American English occurred in a corpus of books? (source: Google Ngram Viewer )