By Luc Cohen Reuters NEW YORK (Reuters) - Starbucks Corp has this year bought coffee beans from China at its highest volume ever, shipping data show, reflecting the country's burgeoning role as bean supplier amid supply concerns among traditional exporters. The world's biggest coffee chain imported nearly 14,000 bags of arabica beans from China into the United States in the first nine months of 2014, more than five times last year's total, according to data from shipping intelligence firm PIERS, which aggregates cargo manifest details from customs data. Customers walk out of a Starbucks coffee store in Shanghai July 28, 2014. Courtesy of Reuters ( CREDIT: REUTERS/ CARLOS BARRIA) That is a fraction of total coffee imports by Starbucks - also the leading overall importer - from across the globe in the January-September period, but the company's purchases represent more than half of China's cof...