Shipments of coal on the Great Lakes totaled 2.7 million tons in July, a slight increase – 63,000 tons – compared to June, but a drop of 12.4 percent compared to a year ago, according to the Lake Carriers' Association. Loadings fell 30.5 percent more when compared to the month’s five-year average, the association said. Only one port range – Lake Michigan – registered an increase over last year at 37.7 percent. Loadings at Lake Superior docks fell 13....