costs . our 2012 results were lower than 2011 when we realized $ 53.1 million in premium-services margins and our storage and marketing margins consisted of $ 96.0 million from realized seasonal price differentials and marketing optimization activities , and $ 87.7 million of storage demand costs . in addition , we recognized a loss on the change in fair value of our nonqualifiying economic storage hedges of $ 1.0 million in 2012 compared with a gain of $ 8.5 million in 2011 . our premium services were impacted negatively by lower natural gas prices and decreased natural gas price volatility . the impact of our hedge strategies and the inability to hedge seasonal price differentials at levels that were available to us in the prior year significantly reduced our storage margins . we also experienced reduced opportunities to optimize our storage assets , which negatively impacted our marketing margins . we realized a loss in our transportation margins of $ 42.4 million in 2012 compared with a loss of $ 18.8 million in 2011 , due primarily to a $ 29.5 million decrease in transportation hedges . our transportation business continues to be impacted by narrow price location differentials and the inability to hedge at levels that were available to us in prior years . as a result of significant increases in the supply of natural gas , primarily from shale gas production across north america and new pipeline infrastructure projects , location and seasonal price differentials narrowed significantly beginning in 2010 and continuing through 2012 . this market change resulted in our transportation contracts being unprofitable impacting our ability to recover our fixed costs . operating costs decreased due primarily to lower employee-related expenses , which includes the impact of fewer employees . we also recognized an expense of $ 10.3 million related to the impairment of our goodwill in the first quarter 2012 . given the significant decline in natural gas prices and its effect on location and seasonal price differentials , we performed an interim impairment assessment in the first quarter 2012 that reduced our goodwill balance to zero . 2011 vs . 2010 - the factors discussed in energy services 2019 201cnarrative description of the business 201d included in item i , business , of this annual report have led to a significant decrease in net margin , including : 2022 a decrease of $ 65.3 million in transportation margins , net of hedging , due primarily to narrower location price differentials and lower hedge settlements in 2011 ; 2022 a decrease of $ 34.3 million in storage and marketing margins , net of hedging activities , due primarily to the following : 2013 lower realized seasonal storage price differentials ; offset partially by 2013 favorable marketing activity and unrealized fair value changes on nonqualifying economic storage hedges ; 2022 a decrease of $ 7.3 million in premium-services margins , associated primarily with the reduction in the value of the fees collected for these services as a result of low commodity prices and reduced natural gas price volatility in the first quarter 2011 compared with the first quarter 2010 ; and 2022 a decrease of $ 4.3 million in financial trading margins , as low natural gas prices and reduced natural gas price volatility limited our financial trading opportunities . additionally , our 2011 net margin includes $ 91.1 million in adjustments to natural gas inventory reflecting the lower of cost or market value . because of the adjustments to our inventory value , we reclassified $ 91.1 million of deferred gains on associated cash flow hedges into earnings . operating costs decreased due primarily to a decrease in ad valorem taxes . selected operating information - the following table sets forth certain selected operating information for our energy services segment for the periods indicated: .

Table:
operating information | years ended december 31 , 2012 | years ended december 31 , 2011 | years ended december 31 , 2010
natural gas marketed ( bcf ) | 709 | 845 | 919
natural gas gross margin ( $ /mcf ) | $ -0.07 ( 0.07 ) | $ 0.06 | $ 0.18
physically settled volumes ( bcf ) | 1433 | 1724 | 1874
natural gas volumes marketed and physically settled volumes decreased in 2012 compared with 2011 due primarily to decreased marketing activities , lower transported volumes and reduced transportation capacity .
the decrease in 2011 compared with 2010 was due primarily to lower volumes transported and reduced transportation capacity .
transportation capacity in certain markets was not utilized due to the economics of the location price differentials as a result of increased supply of natural gas , primarily from shale production , and increased pipeline capacity as a result of new pipeline construction. .

Question: what was the percentage difference in natural gas marketed ( bcf ) between 2011 and 2012?
Answer: -16%
Calculation: subtract(709, 845), divide(#0, 845)