horse and buggy vs horse and carriage

horse and buggy

noun
  • A horse and carriage. 

horse and carriage

noun
  • A light, simple, two-person carriage of the late 18th, 19th and early 20th centuries, drawn usually by one or sometimes by two horses. 

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