relaunch vs replacement

relaunch

noun
  • The act or fact of launching again. 

verb
  • To launch again. 

replacement

noun
  • The act of replacing something. 

  • The removal of an edge of crystal, by one plane or more. 

  • A person or thing that takes the place of another; a substitute. 

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