pre_text: mfc 2019s operating profit for 2013 increased $ 175 million , or 14% ( 14 % ) , compared to 2012 . the increase was primarily attributable to higher operating profit of approximately $ 85 million for air and missile defense programs ( thaad and pac-3 ) due to increased risk retirements and volume ; about $ 85 million for fire control programs ( sniper ae , lantirn ae and apache ) due to increased risk retirements and higher volume ; and approximately $ 75 million for tactical missile programs ( hellfire and various programs ) due to increased risk retirements . the increases were partially offset by lower operating profit of about $ 45 million for the resolution of contractual matters in the second quarter of 2012 ; and approximately $ 15 million for various technical services programs due to lower volume partially offset by increased risk retirements . adjustments not related to volume , including net profit booking rate adjustments and other matters , were approximately $ 100 million higher for 2013 compared to 2012 . 2012 compared to 2011 mfc 2019s net sales for 2012 were comparable to 2011 . net sales decreased approximately $ 130 million due to lower volume and risk retirements on various services programs , and about $ 60 million due to lower volume from fire control systems programs ( primarily sniper ae ; lantirn ae ; and apache ) . the decreases largely were offset by higher net sales of approximately $ 95 million due to higher volume from tactical missile programs ( primarily javelin and hellfire ) and approximately $ 80 million for air and missile defense programs ( primarily pac-3 and thaad ) . mfc 2019s operating profit for 2012 increased $ 187 million , or 17% ( 17 % ) , compared to 2011 . the increase was attributable to higher risk retirements and volume of about $ 95 million from tactical missile programs ( primarily javelin and hellfire ) ; increased risk retirements and volume of approximately $ 60 million for air and missile defense programs ( primarily thaad and pac-3 ) ; and about $ 45 million from a resolution of contractual matters . partially offsetting these increases was lower risk retirements and volume on various programs , including $ 25 million for services programs . adjustments not related to volume , including net profit booking rate adjustments and other matters described above , were approximately $ 145 million higher for 2012 compared to 2011 . backlog backlog increased in 2013 compared to 2012 mainly due to higher orders on the thaad program and lower sales volume compared to new orders on certain fire control systems programs in 2013 , partially offset by lower orders on technical services programs and certain tactical missile programs . backlog increased in 2012 compared to 2011 mainly due to increased orders and lower sales on fire control systems programs ( primarily lantirn ae and sniper ae ) and on various services programs , partially offset by lower orders and higher sales volume on tactical missiles programs . trends we expect mfc 2019s net sales to be flat to slightly down in 2014 compared to 2013 , primarily due to a decrease in net sales on technical services programs partially offset by an increase in net sales from missiles and fire control programs . operating profit is expected to decrease in the high single digit percentage range , driven by a reduction in expected risk retirements in 2014 . accordingly , operating profit margin is expected to slightly decline from 2013 . mission systems and training our mst business segment provides ship and submarine mission and combat systems ; mission systems and sensors for rotary and fixed-wing aircraft ; sea and land-based missile defense systems ; radar systems ; littoral combat ships ; simulation and training services ; and unmanned systems and technologies . mst 2019s major programs include aegis combat system ( aegis ) , lcs , mh-60 , tpq-53 radar system , and mk-41 vertical launching system ( vls ) . mst 2019s operating results included the following ( in millions ) : .
post_text: 2013 compared to 2012 mst 2019s net sales for 2013 decreased $ 426 million , or 6% ( 6 % ) , compared to 2012 . the decrease was primarily attributable to lower net sales of approximately $ 275 million for various ship and aviation systems programs due to lower volume .
table: 2013 2012 2011
table: Net sales $7,153 $7,579 $7,132
table: Operating profit 905 737 645
table: Operating margins 12.7% 9.7% 9.0%
table: Backlog at year-end 10,800 10,700 10,500
question: Analyse this data from a financial earnings document. what was the average operating profit from 2011 to 2013 in millions