megrims vs mulligrubs

megrims

noun
  • Chiefly preceded by the: depression, low spirits, unhappiness. 

  • Any of various diseases of animals, especially horses, marked by a disturbance of equilibrium and abnormal gait and behaviour such as staggers or a sudden vertigo, sometimes followed by unconsciousness; the staggers. 

mulligrubs

noun
  • low spirits, mild depression, the blues 

  • sullenness; sulky behaviour 

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