costumer vs wardrobe mistress

costumer

noun
  • A person who designs, makes or supplies theatrical costumes; a costumier. 

  • A costume drama. 

  • A person who wears a costume or takes part in cosplay. 

wardrobe mistress

noun
  • A woman in charge of the procurement, maintenance, and inventory of the costumes and other clothing worn by performers. 

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