disquiet vs unconcern

disquiet

noun
  • Lack of quiet; absence of tranquility in body or mind 

verb
  • To make (someone or something) worried or anxious. 

unconcern

noun
  • Lack of interest or care; indifference or apathy. 

  • Freedom from worry or apprehensiveness; insouciance or nonchalance. 

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