 Since 1990 the total number of hours flown annually by the GA sector has remained in the range 1 @.@ 25 – 1 @.@ 35 million , the dominant sector being traditional GA flying , which accounts for 0 @.@ 6 million per year . An overall increase in aircraft numbers combined with nil growth in hours flown has brought the annual average <unk> per aircraft down from 157 hours in 1984 to 103 hours in 2002 . The decline in asset <unk> has led to speculation that the economic health of the GA industry is weakening , though the lack of data on profitability makes this difficult to confirm . 
