Smartphone shipments in China plunged 21.8 per cent year on year in May to 23.7 million units, the biggest decline this year, according to the latest data from a government-run research institute. Foreign brands, including Apple’s iPhone, saw shipments drop by 9.7 per cent in May from a year earlier, outperforming local brands. Domestic manufacturers, including Huawei Technologies and Xiaomi, saw their shipments fall a combined 24.2 per cent, according to data released on Friday by the China...