Administrator vs minister-president

Administrator

noun
  • The queen's representative in some Commonwealth territories, comparable to a Governor General. 

minister-president

noun
  • The head of government in a number of European countries or subnational governments, in which a parliamentary or semi-presidential system of government prevails, who presides over the council of ministers. 

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