New airline figures show the Dublin to London route is the second busiest international city route in the world.

The International Air Transport Association (IATA) says last year, 3.6 million people traveled across the Irish Sea, which is an increase of 6.9%. The only busier one is Hong Kong to Taipei.

While generally, global air traffic grew by 5.1% - carrying 3.129 billion passengers in 2013.

Airlines in the Asia-Pacific region carried the largest number of people of any region, at 1.012 billion passengers. Europe saw 825.9 million people take to its skies - an increase of 3.4% over 2012. While 818.9 million took a flight in North America.

The top country based on passengers in Europe was the United Kingdom, which was at 177.9 million air travellers, up 3.7% over 2012.

South Africa topped the list in Africa, while China was the top air traveller in the Asia-Pacific region.

US still largest single air market

The United States saw 618.1 million people travel by air, an increase of 3.3%.

The US is still the largest single air market in the world, in terms of total two-way traffic, international and domestic.

No European carrier makes it into the top five airlines, which are ranked by total number of passengers carried.

Delta Air Lines topped the list with 120.6 million passengers carried last year, followed by Southwest Airlines, China Southern Airlines, United Airlines and American Airlines.

US carrier Delta is the largest global airline | Image: Delta via Facebook

IATA CEO Tony Tyler said "Last year...the industry carried more than 3 billion passengers and nearly 48 million tonnes of cargo on nearly 100,000 flights per day, while the real price of air travel fell by 7.4%."

"Aviation's annual contribution exceeds even these impressive figures. Its global economic impact is estimated at US$2.4 trillion and it supports 3.4% of global GDP. By value, over a third of goods traded internationally are delivered by air and some 58.1 million jobs are supported by aviation," he added.