guinea vs pound sterling

guinea

noun
  • A gold coin originally worth twenty shillings; later (from 1717 until the adoption of decimal currency) standardised at a value of twenty-one shillings. 

  • Synonym of guinea fowl 

  • A person of Italian descent. 

pound sterling

noun
  • The currency of the United Kingdom. 

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