flageolet vs xiao

flageolet

noun
  • A type of small flute of the fipple family. 

  • A type of kidney bean, common in France. 

  • A technique for playing stringed instrument that produces high-pitched overtones. 

xiao

noun
  • A type of Chinese flute. 

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