indifference vs pep

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. 

pep

verb
  • To inject with energy and enthusiasm. 

noun
  • Energy, high spirits. 

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