reject vs sign up

reject

noun
  • A rejected takeoff. 

  • A rejected defective product in a production line. 

  • Something that is rejected. 

  • An unpopular person. 

verb
  • To refuse a romantic advance. 

  • To refuse to accept. 

  • To block a shot, especially if it sends the ball off the court. 

sign up

verb
  • To add one's own name to the list of people who are participating in something (including amateur, but not professional, teams) 

  • To agree to purchase some good or service. 

  • To add a name to the list of people who are participating in something. 

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