Global air passenger traffic growth is up 6% year-over-year in the 1H 2016, according to IATA’s latest Air Passenger Market Analysis, ATWonline reported.

Compared to 5.9% growth in the first half of 2015, the figure includes this year’s extra leap day. IATA estimates that without the extra day, 2016’s first-half growth is 5.4%, which is still “broadly in line with the average pace seen over the past decade,” IATA said. Year-to-date, total market capacity is up 6.2% year-over-year (YOY), with a total passenger load factor of 79.2%.

Total market passenger traffic in June was up 5.2% YOY, improved on May’s 4.8% growth. June capacity was up 5.6% YOY, and the total market load factor came to 80.7%.

“Demand for travel continues to increase, but a slower pace,” IATA DG and CEO Tony Tyler said. “The fragile and uncertain economic backdrop, political shocks and a wave of terrorist attacks are all contributing to a softer demand environment.”

“Loss of momentum can be attributed partly to the ongoing and cumulative impacts of recent high-profile terrorist attacks, which have weighed on international European traffic in particular,” IATA senior economist David Oxley said. “Typically, the impact of such shock events is just transitory, but the repeated nature of recent events suggests that the effects may be longer-lasting this time.”

Nonetheless, passenger demand “continues to be supported somewhat by lower airfares,” Oxley said. “Further stimulus is likely to come through during the rest of 2016 from lagged impacts of prior falls in oil prices.”

Worldwide international passenger traffic was up 5% YOY in June, up 0.7 point from May, but down 1.2 points compared to June 2015. June passenger growth occurred in all of the world regions. Capacity on international routes increased 6.4% YOY, resulting in an international traffic passenger load factor of 79.4%, up 2.3 points from May.

International passenger traffic in Europe—with a 23.8% share of global international travel passengers, the world’s largest—grew only 2.1% YOY in June, the same rate as in May. The terror attacks on airports in Brussels and Istanbul, as well as the attempted coup in Turkey and uncertainty following the UK Brexit vote have all contributed to slowing demand in recent months.

Asia-Pacific carriers—with a 17.4% share of global international passenger traffic—showed 8.2% YOY growth in international passenger traffic in June, up from 5.1% in May. Latin American carriers showed the biggest increase in international traffic demand—up 8.8% YOY, “suggesting that carriers have flown out of the soft patch seen in the first quarter,” IATA said. International passenger travel on Middle East, African and North American carriers were up 7.5%, 4.7% and 4% respectively, YOY.

Combined world traffic on domestic routes increased 5.7% YOY in June, up 0.5 point from May. Capacity on domestic routes increased 4.3% YOY, leading to a total PLF for domestic travel of 83.2%.

With the largest domestic passenger travel market in the world—a 15.4% share—US carriers had 4.5% YOY growth in June, nearly even with May’s 4.4% growth. China, with the second-largest share of domestic traffic (8.4%), had 11.3% YOY domestic travel growth in June, up 1.5 points from May.

Domestic travel in India again had the strongest showing for all of the major domestic markets, with 23.3% YOY growth in June, up 2.1 points from May.

“A big part of the additional [domestic] traffic growth is because airlines are rapidly adding airport-pairs and frequencies, which cuts journey times for passengers and has the same effect on demand as a large cut in fares,” Oxley said. “Both Indian and Chinese airlines are adding more airport-pairs in 2016 which will stimulate travel, but the big difference between the two is that Chines frequencies are not scheduled to increase this year.”

June domestic traffic grew marginally in the rest of the world’s remaining major domestic markets, except for Brazil. Domestic traffic in Russia, Japan and Australia increased 1.3%, 1.2% and 1.1% respectively, YOY.

Brazil’s domestic market traffic fell 6.5% YOY in June. “In addition to the squeeze on incomes, options for Brazilian travelers are curtailed by fewer and less frequent air connections,” Oxley said. Domestic traffic in Brazil is nearly 10% lower than it was in early 2015, IATA said.

“It is too soon to know whether recent terrorist attacks will have a long-term negative influence on demand, nor what will be the impact of Brexit and the events in Turkey,” Tyler said. “But it is vital that governments recognize and support aviation’s ability to contribute to global economic well-being and better understanding across cultural and political borders.”