DM vs diabetes mellitus

DM

verb
  • To Dungeon Master; to perform as a dungeon master; to run a tabletop role-playing game. 

  • To communicate by direct message, usually on a social website. 

noun
  • A Dr. Martens boot or shoe. 

  • driving motor car 

  • Coordinate terms: PM, IM 

  • adamsite, diphenylaminechlorarsine 

diabetes mellitus

noun
  • A medical disorder commonly called diabetes, characterized by varying or persistent hyperglycemia (high blood sugar levels), especially after eating. 

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