grey wolf vs lupus

grey wolf

noun
  • A large canid, Canis lupus, once found throughout forested areas of northern Europe, Asia and America; it shares a common ancestry with the domestic dog. 

lupus

noun
  • Any of a number of autoimmune diseases, the most common of which is systemic lupus erythematosus. 

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