The most important factor to consider, in assessing the state of the shipping industry, is the state of the global economy. The international shipping industry accounts for approximately 90 percent of global trade by volume and is essential for connecting large sectors of the world's economy. Since 1734, the industry has seen more than 20 boom-bust cycles, which occur roughly once per decade. The most recent cycle began in 2004 and peaked in 2008 before declining rapidly at the onset of the global financial crisis. The downturn afflicted each of the industry's three main categories: tanker, dry bulk and container. While the volume of global trade has recovered somewhat — it grew 4 percent in 2011, marking a 16 percent growth in ton-kilometers — the shipping industry is still reeling from the financial crisis. Big, Efficient Fleets The industry right now has far more ships than it needs.