chief executive vs first minister

chief executive

noun
  • The governor of a U.S. state. 

  • Chief executive officer. 

  • The president of the United States. 

  • The head of government of Hong Kong 

  • The head of government of Macau 

first minister

noun
  • The principal minister of a ruler or state. 

  • A leader of a devolved government such as Scotland, Wales, or Northern Ireland. 

  • The prime minister or a provincial or territorial premier. 

How often have the words chief executive and first minister occurred in a corpus of books? (source: Google Ngram Viewer )