The company generated A$3.2 billion (US$2.2 billion) last year, down 20% on the more than A$4 billion generated in 2014.
Dragging down revenue was a 37% slide in the average realised oil price from A$114.2 per barrel in 2014 to an average of A$71.44 per barrel last year.
This offset a 7% jump in production, year-on-year, to 57.7 million barrels of oil equivalent, its highest level since 2007.
Helping
