plus sign vs worth

plus sign

noun
  • The symbol + used to denote the operation of addition, to indicate that a number is positive, and so on. 

worth

noun
  • Value. 

  • Wealth, fortune, riches, property, possessions. 

  • Merit, excellence. 

  • An amount that could be achieved or produced in a specified time. 

adj
  • Deserving of. 

  • Having a value of; proper to be exchanged for. 

  • Making a fair equivalent of, repaying or compensating. 

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