sign of the zodiac vs signing

sign of the zodiac

noun
  • Synonym of zodiac sign 

signing

noun
  • The use of sign language; skill at using a sign language. 

  • The act of concluding a contract, especially by an athlete or entertainer with a company. 

  • A player signed by a sporting organization. 

  • An event (signing session) in a bookshop etc. where an author signs copies of his or her book. 

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