conscript vs sign up

conscript

verb
  • To enrol(l) compulsorily; to draft; to induct. 

adj
  • Drafted into a military service or similar. 

  • Enrolled; written; registered. 

noun
  • A constructed script or writing system, especially for use with a conlang. 

  • One who is compulsorily enrolled, often into a military service; a draftee. 

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