;2016;2017;2018; Operating profit margin. Per cent;18.49;18.42;19.50; Operating margin. Per cent;23.19;30.33;30.06; Return on total assets. Per cent;7.11;8.35;7.59; Return on equity. Per cent;10.50;13.78;9.13; Equity ratio. Per cent;39.17;39.45;46.51; Current ratio;0.97;1.06;1.03; Ratio of fixed assets to long term capital;1.01;0.99;0.99; Debt-to-equity ratio;1.55;1.53;1.15;