qualm vs unconcern

qualm

noun
  • A feeling of apprehension, doubt, fear etc. 

  • A prick of the conscience; a moral scruple, a pang of guilt. 

  • A sudden sickly feeling; queasiness. 

verb
  • To have a sickly feeling. 

unconcern

noun
  • Freedom from worry or apprehensiveness; insouciance or nonchalance. 

  • Lack of interest or care; indifference or apathy. 

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