minister-president vs prime minister

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. 

prime minister

noun
  • In a parliamentary democracy, the chief member of the cabinet and head of the government; often the leader of the majority party. 

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