indifferently vs neutrally

indifferently

adv
  • Tolerably; passably. 

  • Without distinction; impartially, objectively. 

  • Without great care; without sufficient attention or thought. 

neutrally

adv
  • In a neutral manner; evenhandedly or fairly. 

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