Worldwide passenger air traffic grew again last year, albeit at a slightly slower pace, led by the dynamic growth of low-cost air carriers, the International Civil Aviation Organisation reported.

A total of 3.7 billion passengers were transported by the world’s airlines last year, a 6 per cent increase from 2015. That was just under the previous year’s 7.1 per cent rise, the United Nations agency said.

Growth was most pronounced in the Middle East (11.2 per cent), Asia (8 per cent), Latin America (6.5 per cent) and Africa (5.7 per cent), while it was slower in Europe (4.3 per cent) and North America (3.5 per cent).

“Over half of the world’s tourists who travel across international borders each year were transported by air,” the Montreal-based agency noted in a statement.

Low-cost carriers accounted for 28 per cent of all passenger air traffic. Passing a milestone, they transported more than 1 billion passengers for the first time. In Europe, low-cost carriers transported nearly a third of all passengers, slightly more than the 31 per cent in Asia or North America’s 25 per cent.

“The increasing presence of low-cost carriers notably in emerging economies contributed to the overall growth of passenger traffic,” the ICAO said.

As for scheduled domestic flights, North America accounted for 43 per cent of the total, up 4.3 per cent from the previous year, while domestic traffic in Asia was up 10 per cent, largely due to growth in India and China.

Increased traffic and significantly lower fuel costs helped boost airlines’ operating profits, which the ICAO put at US$60 billion for last year, some US$2 billion more than in 2015.

“More than a third of the profits are expected to come from the carriers of North America, whose domestic market represents 66 per cent of their total operations,” the agency reported.