councilmember vs parliamentarian

councilmember

noun
  • A councilman or councilwoman; member of a council. 

parliamentarian

noun
  • A member of a parliament, congress or an elected national legislative body of another name. 

  • An officer in most legislative bodies charged with being well-versed in the parliamentary rules of that legislative house, and whose rulings are taken as authoritative, to be appealed only to the whole of the house itself under special rules. 

  • A person well-versed in parliamentary procedure. 

adj
  • Of or relating to a parliament; favouring the establishment of a parliament. 

  • Of or relating to the Parliamentarians (supporters of the parliament during the English Civil War (1642–1651)). 

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