I vs thoo

I

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

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

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

noun
  • Interstate. 

  • The ego. 

thoo

pron
  • Thou; singular informal form of you. 

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