first minister vs warden

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. 

warden

noun
  • A governing official in various institutions 

  • An official charged with supervisory duties or with the enforcement of specific laws or regulations; such as a game warden or air-raid warden 

  • A variety of pear. 

  • A chief administrative officer of a prison. 

verb
  • To carry out the duties of a warden. 

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