hobgoblin vs human immunodeficiency virus

hobgoblin

noun
  • A small, ugly goblin that makes trouble for humans. 

  • A source of dread, fear or apprehension; a bugbear. 

human immunodeficiency virus

noun
  • Either of the two related viruses, human immunodeficiency virus 1 (HIV-1) and human immunodeficiency virus 2 (HIV-2) that progressively destroy the body's immune system and can potentially lead to AIDS. 

How often have the words hobgoblin and human immunodeficiency virus occurred in a corpus of books? (source: Google Ngram Viewer )