carefreeness vs unconcern

carefreeness

noun
  • The property of being lighthearted, joyous, cheerful, without a care. 

unconcern

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

  • Freedom from worry or apprehensiveness; insouciance or nonchalance. 

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