euphonium vs flugelhorn

euphonium

noun
  • A valved brass instrument with conical tubing similar in appearance to a tuba but of higher pitch; a sax horn. 

flugelhorn

noun
  • A brass instrument resembling a cornet but with a wider, conical bore, and usually with three valves, in the same B-flat pitch as many trumpets and cornets but with a more deeply conical mouthpiece than those. A bugle with valves. 

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