Airlines worldwide will need an average of 31,000 new pilots every year for the next two decades as the air-transport industry expands, Boeing forecast Monday. In its annual projection of industry staffing needs, the U.S. aerospace giant said demand for flight attendants also will grow sharply to 814,000 people through 2035, while demand for maintenance technicians will rise to 679,000. Those numbers will be needed to serve a global fleet Boeing has predicted will increase by nearly 40,000 aircraft in the same period. The pilot estimate was 10.5 percent higher than last year's forecast, Boeing said in a statement. Expected growth is strongest in the Asia-Pacific region, with 40 percent of global demand due to the rise of low-cost carriers using single-aisle airplanes like the Boeing 737 and the Airbus A320. New aviation markets in Cuba and Mexico will drive stronger demand in North America, Boeing said.