p vs penny sterling

p

noun
  • proton 

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

penny sterling

noun
  • A British coin worth  1⁄240 of a pound sterling, made of silver prior to 1496, and copper thereafter, Abbreviation: d. 

  • A unit of weight amounting to 1/20 of a troy ounce. 

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