cabriolet vs ragtop

cabriolet

noun
  • An automobile with a retractable top. 

  • A light two- or four-wheeled carriage with a folding top, pulled by a single horse. 

ragtop

noun
  • A convertible automobile. 

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