Guinea vs Republic of Guinea

Guinea

name
  • A country in West Africa. Official name: Republic of Guinea. 

  • Someone of Italian descent in the United States. 

  • The coast of West Africa between Morocco and the Congo, particularly the north shore of the Gulf of Guinea. 

Republic of Guinea

name
  • The official name of Guinea. 

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