The absence of major air disasters in 2017 reflects a continuous improvement in air security, but the goal of zero total accidents remains a challenge in a sky jammed with aircraft, according to a report by the French Press Agency. A total of 10 crashes of civil passenger and cargo planes claimed 44 lives, said the Aviation Safety Network in a statement published Monday. "The year 2017 turned out to be the safest year ever for commercial aviation," ASN said. Five of the fatal accidents involved cargo flights and five passenger flights. The previous year, ASN recorded 16 accidents and 303 lives lost. No major airline crashed a plane, the To70 agency said in its annual report, also published Monday. "The past year has been another exceptionally good year for civil aviation safety," To70 said. "2017 was much better than could reasonably (and statistically) be expected, and was again better than last years remarkable performance," said To70 researcher Adrian Young. The chances of dying in a plane crash are now one in 16 million, Young said, making air travel the safest means of transport even as worldwide air traffic grew by three percent in 2017 over 2016. The To70 report used data from the International Air Transport Association (IATA) which is to issue its own annual report soon. Accidents involving military planes, including military transport aircraft, were not taken into account in the study. ASN President Harro Ranter said the low number of accidents was "no surprise," coming after a steady decline of fatalities in recent years. But "despite the good news, a note of caution needs to be sounded," the To70 report warned. "Whilst the safety levels of modern civil passenger airplanes remain high, the extraordinarily low accident rate this year must be seen as a case of good fortune," it said. One worry for the future is the many pieces of electronic equipment that passengers carry in luggage because of the risk of fire or the danger of lithium-ion batteries exploding, the report said.