sign for vs sign up

sign for

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 sign for and sign up occurred in a corpus of books? (source: Google Ngram Viewer )