Munich (dpa) - German business with Russia dropped further in 2015 as Moscow remained mired in an economic crisis following a fall in oil prices, according to a study by consultancy firm EAC published on Wednesday.The 30 large companies listed on the Frankfurt Stock Market‘s main DAX index would only generate a 15-billion-euro (15,9-billion-dollar) turnover in Russia this year, said EAC‘s Dietmar Kusch.Two years ago German companies still reported a turnover of 22 billion euros. In 2014, turnover stood at 19 billion euros.Apart from the drop in oil prices, other factors were the devaluation of the rouble and economic sanctions imposed by the European Union in 2014 over the war in Ukraine.The companies with the highest turnover in Russia last year were carmakers Volkswagen, Daimler and BMW as well as Siemens, energy company Eon and chemicals company BASF.According to the report, turnover on average dropped in double figures, while profit margins shrank from 7 per cent to 4 per cent on average.