Louis IX of France vs Saint Louis

Louis IX of France

Saint Louis

name
  • A river in northeastern Minnesota, United States. 

  • A commune of the Haut-Rhin department, Alsace, France. 

  • A city in northern Senegal, near the mouth of the Senegal River. 

  • A city in southwestern Réunion in Indian Ocean. 

  • A city in eastern Missouri, United States, near the confluence of the Mississippi and Missouri rivers and formerly important in the United States' westward expansion. 

How often have the words Louis IX of France and Saint Louis occurred in a corpus of books? (source: Google Ngram Viewer )