Royal Dutch Shell (RDSa.L), Europe’s largest oil company, reported its lowest annual income in over a decade on Thursday and said it would take further steps to cut costs to cope with weak oil prices if needed. Shell, whose shareholders last week approved its takeover of rival BG Group (BG.L), said 2015 income fell 87 percent to $1.94 billion (1.33 billion pound), in line with analysts’ estimates, as its oil and gas production unit took a big hit from slumping oil prices.