As demand for freighter aircraft continues to trend higher, the air freight market will need about 125 new freighters per year to meet growth and replacement needs over the next 20 years, according to forecast issued Tuesday by global consultancy Air Cargo Management Group. ACMG’s forecast for 2015 assumes a “baseline-growth” scenario, which uses a 4.5-percent annual growth rate in freight ton kilometers (FTKs). The projection compares favorably to the average of 95 freighters (production units and passenger-to-freighter conversions) added per year from 1990 to 2014.

Even under an extreme case scenario in which air cargo demand did not grow at all over the next 20 years, ACMG calculates a need for about 60 added freighters per year to offset the capacity of freighters retired from the existing fleet.

“Some vigor returned to the air freight market last year, and that has only continued this year,” said Robert Dahl, managing director of ACMG and one of the forecast’s authors. “When looking over the long term, the outlook for freighters is healthy.”

The freighter aircraft market has undergone a period of significant change since 2000, said the report. Global air freight demand has experienced an unprecedented level of volatility since 2000; in fact, three of the worst years ever in terms of air freight traffic declines (measured in terms of freight-ton-kilometers performed) have taken place since 2000. The jet freighter fleet peaked in size at 1,800 units in 2006-2007, but then contracted. The fleet total has hovered at some 1,600 units since 2009. The total increased by about 50 units in 2014, to reach a level of 1,609 at the beginning of this year. The baseline forecast calls for the fleet to grow to 2,887 units through 2034.

“Despite challenges facing the freighter market in the post-recession period, there continue to be new developments that will have an impact on the market going forward,” Dahl said. “The news on the freighter front over the past year was a mix of good and bad, with most of the good news coming in the narrowbody sector.”