( $ 66 million net-of-tax ) as a result of customer credits to be realized by electric customers of entergy louisiana , consistent with the terms of the stipulated settlement in the business combination proceeding . see note 2 to the financial statements for further discussion of the business combination and customer credits . results of operations for 2015 also include the sale in december 2015 of the 583 mw rhode island state energy center for a realized gain of $ 154 million ( $ 100 million net-of-tax ) on the sale and the $ 77 million ( $ 47 million net-of-tax ) write-off and regulatory charges to recognize that a portion of the assets associated with the waterford 3 replacement steam generator project is no longer probable of recovery . see note 14 to the financial statements for further discussion of the rhode island state energy center sale . see note 2 to the financial statements for further discussion of the waterford 3 replacement steam generator prudence review proceeding . net revenue utility following is an analysis of the change in net revenue comparing 2016 to 2015 . amount ( in millions ) .
what portion of the net change in net revenue during 2016 is related to the change in retail electric price?
the retail electric price variance is primarily due to : 2022 an increase in base rates at entergy arkansas , as approved by the apsc . the new rates were effective february 24 , 2016 and began billing with the first billing cycle of april 2016 . the increase included an interim base rate adjustment surcharge , effective with the first billing cycle of april 2016 , to recover the incremental revenue requirement for the period february 24 , 2016 through march 31 , 2016 . a significant portion of the increase was related to the purchase of power block 2 of the union power station ; 2022 an increase in the purchased power and capacity acquisition cost recovery rider for entergy new orleans , as approved by the city council , effective with the first billing cycle of march 2016 , primarily related to the purchase of power block 1 of the union power station ; 2022 an increase in formula rate plan revenues for entergy louisiana , implemented with the first billing cycle of march 2016 , to collect the estimated first-year revenue requirement related to the purchase of power blocks 3 and 4 of the union power station ; and 2022 an increase in revenues at entergy mississippi , as approved by the mpsc , effective with the first billing cycle of july 2016 , and an increase in revenues collected through the storm damage rider . see note 2 to the financial statements for further discussion of the rate proceedings . see note 14 to the financial statements for discussion of the union power station purchase . the louisiana business combination customer credits variance is due to a regulatory liability of $ 107 million recorded by entergy in october 2015 as a result of the entergy gulf states louisiana and entergy louisiana business combination . consistent with the terms of the stipulated settlement in the business combination proceeding , electric customers of entergy louisiana will realize customer credits associated with the business combination ; accordingly , in october 2015 , entergy recorded a regulatory liability of $ 107 million ( $ 66 million net-of-tax ) . these costs are being entergy corporation and subsidiaries management 2019s financial discussion and analysis .