British English vs Commonwealth 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. 

Commonwealth English

noun
  • The generalised variety of English spoken and written primarily in the United Kingdom and its former colonies, frequently excluding Canada; always excluding the United States of America. (ie. non-North American English) 

  • The group of varieties of English used in the ex-colonial member states of the Commonwealth of Nations, in distinction to the varieties used in Britain itself 

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