first-rate vs spiffing

first-rate

adj

  • Superb, exceptional; of the best sort; very high quality. 

  • Of a Royal Navy ship of the line in the Napoleonic Era: having at least 100 guns across three gun decks, a complement of 850–875, and weighing approximately 2,500 tons burthen. 

noun

  • A first-rate ship of the line. 

spiffing

adj

  • Very good, excellent. 

  • Smart or appealing in dress or appearance. 

How often have the words first-rate and spiffing occurred in a corpus of books? (source: Google Ngram Viewer )