Analyze the underlying drivers of the change in Tesco's return on equity in 2014.

INCOME STATEMENT Revenue Cost of Sales SG&A Operating profit Net non-recurring income or expense Pre-Tax Profit Tesco Bank Investment and interest income Interest expense Profit before taxes Tax expense Profit after taxes Profit/loss to non-controlling interest Net profit to ordinary shareholders BALANCE SHEET ASSETS Non-current tangible assets Non-current intangible assets Minority equity investments Other non-operating investments Net investment in Tesco Bank Deferred tax asset Derivatives Total non-current assets 2016 54,905.0 (51,417) (1, 734) 1,754.0 (450.0) 77.0 (59.0) (1,177.0) 145.0 (87.0) 58.0 14.0 72.0 2016 25,475.0 1,615.0 668.0 385.0 2,478.0 707.0 1,589.0 32,917.0 2015 52,978.0 (49,227) (1,836) 1,915.0 (564.0) 161.0 8.0 (1,318.0) 202.0 54.0 256.0 9.0 265.0 2015 25,636.0 1,700 0 709.0 430.0 2,374.0 49.0 1,708 0 32,606 0 2014 61,260.0 (58,639) (1,827) 794.0 (6,112.0) 194.0 77.0 (1,329.0) (6,376.0) 657.0 (5,719.0) 25.0 (5,694.0) 2014 30,051.0 2,548.0 860.0 312.0 2,241.0 514.0 1,699 0 38,225.0 2013 62,554.0 (57,239) (1,657) 3,658.0 (456.0) 194.0 192.0 (1,329.0) 2,259.0 (347.0) 1,912.0 4.0 1,916.0 2013 34,308.0 2,542.0 209.0 392.0 2,168.0 73.0 1,576.0 41,268.0