I vs Yi

I

character
  • The ninth letter of the English alphabet, called i and written in the Latin script. 

pron
  • The speaker or writer, referred to as the grammatical subject, of a sentence. 

  • The speaker or writer, referred to as the grammatical object, of a sentence. 

noun
  • Interstate. 

  • The ego. 

Yi

noun
  • An ethnic group who live primarily in mountainous areas of southwest China. 

name
  • A surname. 

  • A surname from Korean. Equivalent to Chinese 李 (Lǐ) 

  • Any of a family of Tibeto-Burman languages spoken by this people. 

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