According to a Global Market Forecast by Airbus, there will be a worldwide demand for 28,200 aircraft – including both passenger and freighter – between 2012 and 2032. Out of these, about 27,350 will be passenger aircraft. Passenger traffic is expected to grow at an average annual rate of 4.7 percent worldwide during this 20 year period. More than half of this growth would likely take place due to growth in emerging economic regions. Other factors behind the growth are increasing urbanisation in many areas of the world and the rise in the middle class population in the high growth areas, which is expected to double during the period. A third of the air traffic by 2031 is expected to be domestic traffic in the biggest air traffic regions – the US, China, Western Europe and India. China is expected to become the largest domestic traffic region by 2032, overtaking the US.