The Middle East’s biggest airline, Emirates, says its profits jumped by about 56 percent to $1.9 billion in the last fiscal year largely due to lower oil prices that drove down fuel operating costs.

The Dubai government-owned airline says revenue, however, fell by four percent to $23.2 billion, mostly because of a stronger U.S. dollar that impacted currency exchange.

Emirates President Tim Clark told The Associated Press on Tuesday that despite the drop in revenue, the airline’s fuel bill decreased to $5.4 billion over the last year, comprising around a fifth of operating costs, compared to 35 percent in 2014.

The airline’s parent company, Emirates Group, which includes the Dnata ground and travel services provider, reported that profits rose to $2.2 billion, though revenue fell three percent to $25.3 billion.