concordat vs pact

concordat

noun
  • A formal agreement between two parties, especially between a church and a state; specifically, an agreement between the Pope and a government. 

pact

noun
  • An agreement; a compact; a covenant. 

  • An alliance or coalition. 

  • An agreement between two or more nations 

verb
  • To form a pact; to agree formally. 

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