Yonex' sales jumped by 24 percent to 31.3 billion yen (€258.9m-$274.4m) in the six months through Sept. 30, but most of the growth took place in China, where the company's recently opened joint venture lifted its sales in the country by 241 percent to ¥8.8 billion (€72.8m-$77.1m), driven by badminton. ...