premise: They are demanding a 6.5 percent increase in wages and a 50 percent rise in bonuses. Of the 1,126 pilots who voted, 897 supported the strike, the union said.
  The pilots earlier rejected a proposal by the government's arbitration body for a 2.5 percent increase in wages and a 50 percent rise in bonuses.
  Korean Air officials said the pilots had been given enough incentives this year, including special allowances amounting to 11.4 percent of their annual pay.
  Due to mounting fuel costs, Korean Air suffered a net loss of 42.5 billion won (40 million dollars) in the second quarter to June but in the third quarter, net profit jumped 59 percent from a year earlier to 154.2 billion won, helped by growth in passenger demand and lower costs.
   What caused net profit to jump up 59% from the previous year?
hypothesis: growth in passenger demand and lower costs