The number of international air passengers traveling in premium classes increased 1.8 percent year over year in June,

according to the International Air Transport Association. While that growth rate was lower than the 2.5 percent increase in international economy passengers, IATA noted that the numbers are "distorted by the comparison with volatile figures last June" and that during the first half of 2014, premium traffic growth has outpaced that of economy traffic. Premium revenue share also is growing because premium yields have been strong, especially in longer-haul markets, according to IATA. The largest percentage growth in June premium traffic occurred on North America-Central America routes (9.7 percent), routes across the Mid-Atlantic (9 percent) and within North America (7.1 percent). Premium traffic on heavily traveled North Atlantic routes was up 3.4 percent. June premium traffic performance was weakest within South America (down 9 percent) and the Far East (down 5.4 percent).