BEIJING, CHINA (Reuters) — Full-year gold demand of the global market in 2015 was virtually unchanged compared with 2014, down just a fraction of 14 metric tons to 4,212 metric tons, said a report released by the World Gold Council last week. The gold market faced a number of challenges in the first half of the year, with demand declining by 6 percent year-on-year, due to a sluggish first quarter followed by a very weak second quarter. […]