indifferently vs unconcernedly

indifferently

adv
  • Without distinction; impartially, objectively. 

  • Tolerably; passably. 

  • Without great care; without sufficient attention or thought. 

unconcernedly

adv
  • In an unconcerned manner. 

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