customer vs nonowner

customer

noun
  • A patron, a client; one who purchases or receives a product or service from a business or merchant, or intends to do so. 

  • A native official who exacted customs duties. 

  • A person, especially one engaging in some sort of interaction with others. 

nonowner

noun
  • One who is not an owner, especially in a business enterprise. 

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