Chinese wolfberry vs goji

Chinese wolfberry

noun
  • Either of two Chinese species of spiny shrub in the nightshade family, Lycium barbarum and Lycium chinense, and their edible fruits, which are used in East Asian traditional medicine. 

goji

noun
  • A fruit in the genus Lycium, especially in commercial products where it is promoted as a superfruit. 

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