Guinean vs guinea

Guinean

noun
  • Someone from Guinea or of Guinean descent. 

adj
  • From Guinea. 

  • From Guinea-Bissau. 

guinea

noun
  • Synonym of guinea fowl 

  • A person of Italian descent. 

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

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