foofoo vs fufu

foofoo

fufu

noun
  • A dish of boiled, mashed cassava mixed with plantain, yams, or other starchy vegetables, common as food in West and Equatorial Africa and the Caribbean. Sold in speciality stores (US) in dry powdered or granulated form. 

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