affect vs make a difference

affect

verb
  • To influence or alter. 

  • To make a show of; to put on a pretense of; to feign; to assume. To make a false display of. 

  • To feel affection for (someone); to like, be fond of. 

  • To burden (property) with a fixed charge or payment, or other condition or restriction. 

  • To move to emotion. 

  • Of an illness or condition, to infect or harm (a part of the body). 

noun
  • A subjective feeling experienced in response to a thought or other stimulus; mood, emotion, especially as demonstrated in external physical signs. 

make a difference

verb
  • To carry out an action, the result of which is a significant change, or an altered circumstance. 

  • To be of importance; to matter. 

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