commercial traveler vs drummer

commercial traveler

drummer

noun
  • One who plays the drums. 

  • A drumstick (the lower part of a chicken or turkey leg). 

  • A housebreaker. 

  • Any of various fish of the family Kyphosidae, which make a drumming sound. 

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