According to new statistics from the International Air Transport Association (IATA) passenger demand fell by 3.5% in 2009 with an average load factor of 75.6%.
IATA revealed that the full-year demand statistics for international air traffic recorded the largest ever post-war decline.
Airfreight also posted a full-year decline of 10.1% with an average load factor of 49.1%.
IATA's director general and CEO Giovanni Bisignani said the industry had permanently lost 2.5 years of growth in passenger markets and 3.5 years of growth in the freight business.
Year-end results proved encouraging as international passenger capacity fell by 0.7% in December 2009, while freight capacity increased by 0.6% compared to December 2008.
Industry's yields also improved in recent months although they were still 5%-10% below last year.
Revenue improvements and profitability will be even slower to recover and airlines are expected to lose an estimated $5.6bn in 2010.
In comparison with November 2009 demand, figures for December reveal a 1.6% rise in passenger traffic, while freight remained basically flat with a 0.2% decline.
International passenger demand in December 2009 showed a 4.5% rise compared with December 2008 with a load factor of 77.6%.
International freight demand in December 2009 posted a 24.4% increase compared with December 2008, with a load factor of 54.1%.