indifference vs one-track mind

indifference

noun
  • Unconcerned nonchalance. 

  • The state of being indifferent. 

  • Unbiased impartiality. 

  • Unemotional apathy. 

  • Self-identity defined through the negation of difference, non-difference. 

  • A lack of enthusiasm. 

one-track mind

noun
  • That said to be possessed by someone who is obsessed with something or only able to think of one thing. 

How often have the words indifference and one-track mind occurred in a corpus of books? (source: Google Ngram Viewer )