bellyache vs mulligrubs

bellyache

verb
  • To unnecessarily complain or whine, often about simple matters. 

noun
  • Any pain in the belly, stomach, or abdomen. 

mulligrubs

noun
  • sullenness; sulky behaviour 

  • low spirits, mild depression, the blues 

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