The American Iron and Steel Institute (AISI) reported that U.S. steel mills shipped 6,035,000 net tons in December 2009, an 11.3% increase from the 5,424,000 net tons shipped in November 2009. It was also a 30.8% increase from the 4,613,000 net tons shipped a year ago, in December 2008. A month-to-month comparison of shipments shows the following changes: hot-rolled sheet, up 21%; hot-dipped galvanized sheet and strip, up 6%; and cold-rolled sheet, up 3%. AISI's member companies represent approximately 75% of both U.S. and North American steel capacity.