Asia-Pacific-connected markets are expected to lead the industry's air cargo growth, with domestic China and intra-Asia traffic leading at eight per cent and 6.9 per cent respectively over plane maker Boeing's next 20-year forecast period. North America-Asia, Europe-South Asia, Europe-Asia, and Europe-Middle East also will be above the world average, Boeing says. Boeing also says the global air cargo market will expand at a 5.2 per cent annual rate over the next 20 years, driven by world gross domestic product (GDP) that will close-to-double over the forecast period. Boeing says the world freighter fleet will increase to 3,198 airplanes from 1,738 by 2031. Large freighters - such as the Boeing 747 and 777 - will represent 36 per cent of the fleet, compared to 31 per cent today.