purchased scrap metal from third-parties ) that were either divested or permanently closed in december 2014 ( see global rolled products below ) . intersegment sales for this segment improved 12% ( 12 % ) in 2014 compared with 2013 , principally due to an increase in average realized price , driven by higher regional premiums , and higher demand from the midstream and downstream businesses . atoi for the primary metals segment decreased $ 439 in 2015 compared with 2014 , primarily caused by both the previously mentioned lower average realized aluminum price and lower energy sales , higher energy costs ( mostly in spain as the 2014 interruptibility rights were more favorable than the 2015 structure ) , and an unfavorable impact related to the curtailment of the s e3o lu eds smelter . these negative impacts were somewhat offset by net favorable foreign currency movements due to a stronger u.s . dollar against most major currencies , net productivity improvements , the absence of a write-off of inventory related to the permanent closure of the portovesme , point henry , and massena east smelters ( $ 44 ) , and a lower equity loss related to the joint venture in saudi arabia , including the absence of restart costs for one of the potlines that was previously shut down due to a period of instability . atoi for this segment climbed $ 614 in 2014 compared with 2013 , principally related to a higher average realized aluminum price ; the previously mentioned energy sales in brazil ; net productivity improvements ; net favorable foreign currency movements due to a stronger u.s . dollar against all major currencies ; lower costs for carbon and alumina ; and the absence of costs related to a planned maintenance outage in 2013 at a power plant in australia . these positive impacts were slightly offset by an unfavorable impact associated with the 2013 and 2014 capacity reductions described above , including a write-off of inventory related to the permanent closure of the portovesme , point henry , and massena east smelters ( $ 44 ) , and higher energy costs ( particularly in spain ) , labor , and maintenance . in 2016 , aluminum production will be approximately 450 kmt lower and third-party sales will reflect the absence of approximately $ 400 both as a result of the 2015 curtailment and closure actions . also , energy sales in brazil will be negatively impacted by a decline in energy prices , while net productivity improvements are anticipated . global rolled products .
what was the percentual decrease observed in alcoa 2019s average realized price per metric ton of aluminum during 2014 and 2015?
* generally , average realized price per metric ton of aluminum includes two elements : a ) the price of metal ( the underlying base metal component plus a regional premium 2013 see the footnote to the table in primary metals above for a description of these two components ) , and b ) the conversion price , which represents the incremental price over the metal price component that is associated with converting primary aluminum into sheet and plate . in this circumstance , the metal price component is a pass- through to this segment 2019s customers with limited exception ( e.g. , fixed-priced contracts , certain regional premiums ) . this segment represents alcoa 2019s midstream operations and produces aluminum sheet and plate for a variety of end markets . approximately one-half of the third-party shipments in this segment consist of sheet sold directly to customers in the packaging end market for the production of aluminum cans ( beverage , food , and pet food ) . seasonal increases in can sheet sales are generally experienced in the second and third quarters of the year . this segment also includes sheet and plate sold directly to customers and through distributors related to the aerospace , automotive , commercial transportation , building and construction , and industrial products ( mainly used in the production of machinery and equipment and consumer durables ) end markets . a small portion of this segment also produces aseptic foil for the packaging end market . while the customer base for flat-rolled products is large , a significant amount of sales of sheet and plate is to a relatively small number of customers . in this circumstance , the sales and costs and expenses of this segment are transacted in the local currency of the respective operations , which are mostly the u.s . dollar , the euro , the russian ruble , the brazilian real , and the british pound. .