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 ) , littoral combat ship ( lcs ) , mh-60 , tpq-53 radar system and mk-41 vertical launching system . mst 2019s operating results included the following ( in millions ) : .

2014: net sales: 7147
operating profit: 843
operating margins: -11.8
backlog at year-end: 11700
2013: net sales: 7153
operating profit: 905
operating margins: -12.7
backlog at year-end: 10800
2012: net sales: 7579
operating profit: 737
operating margins: -9.7
backlog at year-end: 10700

2014 compared to 2013 mst 2019s net sales for 2014 were comparable to 2013 . net sales decreased by approximately $ 85 million for undersea systems programs due to decreased volume and deliveries ; and about $ 55 million related to the settlements of contract cost matters on certain programs ( including a portion of the terminated presidential helicopter program ) in 2013 that were not repeated in 2014 . the decreases were offset by higher net sales of approximately $ 80 million for integrated warfare systems and sensors programs due to increased volume ( primarily space fence ) ; and approximately $ 40 million for training and logistics solutions programs due to increased deliveries ( primarily close combat tactical trainer ) . mst 2019s operating profit for 2014 decreased $ 62 million , or 7% ( 7 % ) , compared to 2013 . the decrease was primarily attributable to lower operating profit of approximately $ 120 million related to the settlements of contract cost matters on certain programs ( including a portion of the terminated presidential helicopter program ) in 2013 that were not repeated in 2014 ; and approximately $ 45 million due to higher reserves recorded on certain training and logistics solutions programs . the decreases were partially offset by higher operating profit of approximately $ 45 million for performance matters and reserves recorded in 2013 that were not repeated in 2014 ; and about $ 60 million for various programs due to increased risk retirements ( including mh-60 and radar surveillance programs ) . adjustments not related to volume , including net profit booking rate adjustments and other matters , were approximately $ 50 million lower for 2014 compared to 2013 . 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 ( primarily ptds as final surveillance system deliveries occurred during the second quarter of 2012 ) ; about $ 195 million for various integrated warfare systems and sensors programs ( primarily naval systems ) due to lower volume ; approximately $ 65 million for various training and logistics programs due to lower volume ; and about $ 55 million for the aegis program due to lower volume . the decreases were partially offset by higher net sales of about $ 155 million for the lcs program due to increased volume . mst 2019s operating profit for 2013 increased $ 168 million , or 23% ( 23 % ) , compared to 2012 . the increase was primarily attributable to higher operating profit of approximately $ 120 million related to the settlement of contract cost matters on certain programs ( including a portion of the terminated presidential helicopter program ) ; about $ 55 million for integrated warfare systems and sensors programs ( primarily radar and halifax class modernization programs ) due to increased risk retirements ; and approximately $ 30 million for undersea systems programs due to increased risk retirements . the increases were partially offset by lower operating profit of about $ 55 million for training and logistics programs , primarily due to the recording of approximately $ 30 million of charges mostly related to lower-of-cost-or-market considerations ; and about $ 25 million for ship and aviation systems programs ( primarily ptds ) due to lower risk retirements and volume . operating profit related to the lcs program was comparable . adjustments not related to volume , including net profit booking rate adjustments and other matters , were approximately $ 170 million higher for 2013 compared to 2012 . backlog backlog increased in 2014 compared to 2013 primarily due to higher orders on new program starts ( such as space fence ) . backlog increased slightly in 2013 compared to 2012 mainly due to higher orders and lower sales on integrated warfare system and sensors programs ( primarily aegis ) and lower sales on various service programs , partially offset by lower orders on ship and aviation systems ( primarily mh-60 ) . .

Questions:
what was the change in net sales for mst from 2012 to 2013?
and what was the total of net sales in 2012?
how much, then, does that change represent in relation to this total?

Answers:
-426
7579
-5.6%