. employees 2013 employee levels were up 5% ( 5 % ) in 2011 versus 2010 , driven by a 3% ( 3 % ) increase in volume levels , a higher number of trainmen , engineers , and yard employees receiving training during the year , and increased work on capital projects . employee levels were down 1% ( 1 % ) in 2010 compared to 2009 despite a 13% ( 13 % ) increase in volume levels . we leveraged the additional volumes through network efficiencies and other productivity initiatives