p vs v

p

character

  • The sixteenth letter of the English alphabet, called pee and written in the Latin script. 

noun

  • proton 

v

character

  • The twenty-second letter of the English alphabet, called vee and written in the Latin script. 

noun

  • a shape resembling the letter v 

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