dress suit vs tail coat

dress suit

noun
  • A type of formal attire for men, normally consisting of a jacket (traditionally with tails), trousers, waistcoat, shirt and tie (traditionally a bow tie). 

  • A type of formal attire for women, typically a jacket over a dress, or a jacket and blouse with trousers or a skirt. 

tail coat

How often have the words dress suit and tail coat occurred in a corpus of books? (source: Google Ngram Viewer )