sole proprietor vs trade name

sole proprietor

noun
  • The person who owns and controls a sole proprietorship. 

trade name

noun
  • The name under which a business or firm operates. 

  • A name used to identify a commercial product or service; may or may not be registered as a trademark. 

How often have the words sole proprietor and trade name occurred in a corpus of books? (source: Google Ngram Viewer )