Data for quarterly price movements in these components can be found using Infoshare. Go to "Economic indicators" then "Consumers Price Index" then "CPI Level 3 Classes for New Zealand". The numbers are currently indexed so that the base quarter ended June 2006 equals 1000. For the quarter ended September 2010 international air transport stood at 1018 (+1.80%) while domestic air transport dropped to 906 (-9.40%). Over the same four years and three months period the overall CPI had risen to 1111 (+11.10%). Note, however, the regular seasonal peaks in the international air transport price index.
In real terms the cost of air travel has been declining for decades, driven in part by technology change as airliners become more efficient, but also by increased productivity in the airline industry and greater competition following economic deregulation. This has been highlighted by the drive to become "low-cost" airlines. A trend to "no-frills" product, particularly for short-haul routes, has also been reducing the headline price of airfares as passengers now pay separately for extra services. Statistics New Zealand notes that it has made some adjustments for these quality of service changes.