;2017;2018;2019; Net operating surplus as a percentage of gross operating revenues (per cent);4.3;3.8;2.6; Annual accumulated surplus/deficit as a percentage of gross operating revenues;1.5;1.6;2.1; Working capital excl. pension premium deviation as a percentage of gross operat;15.9;17.4;19.2; Net interest rate exposure as a percentage of gross operating revenues (per cent;18.6;21.0;27.4; Net loan debt as a percentage of gross operating revenues (per cent);78.8;81.7;82.9; Unrestricted revenues per capita (NOK);12863;13033;13438; Free equity operational account (per cent);11.6;12.6;12.3; Gross investment expenditures as a percentage of gross operating revenues (per c;18.4;20.1;22.3; Self-investment financing as a percentage of total gross investment expenditures;48.9;55.1;64.8;