pass off vs swap out

pass off

verb
  • To give something (to someone). 

  • To abate, to cease gradually. 

  • To happen. 

swap out

verb
  • To exchange (something) for (something else). (usually followed by with or for) 

  • To transfer (memory contents) into a swap file. 

  • To exchange (something or someone) for an unused (or less-used) equivalent. 

noun
  • Anything that is swapped out for another; an exchange. 

  • A pre-prepared food item used in place of an unfinished food item in order to cut down the overall preparation time during filming. 

How often have the words pass off and swap out occurred in a corpus of books? (source: Google Ngram Viewer )