Chinese wolfberry vs goji berry

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 berry

noun
  • Synonym of wolfberry 

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