whpthomas/finqa-parquet huggingface dataset:
entergy corporation and subsidiaries management 2019s financial discussion and analysis regulatory asset associated with new nuclear generation development costs as a result of a joint stipulation entered into with the mississippi public utilities staff , subsequently approved by the mpsc , in which entergy mississippi agreed not to pursue recovery of the costs deferred by an mpsc order in the new nuclear generation docket . see note 2 to the financial statements for further discussion of the new nuclear generation development costs and the joint stipulation . net revenue utility following is an analysis of the change in net revenue comparing 2015 to 2014 . amount ( in millions ) .
what percentage of net revenue of 2015 is attributed to the growth from to retail electric price?
the retail electric price variance is primarily due to : 2022 formula rate plan increases at entergy louisiana , as approved by the lpsc , effective december 2014 and january 2015 ; 2022 an increase in energy efficiency rider revenue primarily due to increases in the energy efficiency rider at entergy arkansas , as approved by the apsc , effective july 2015 and july 2014 , and new energy efficiency riders at entergy louisiana and entergy mississippi that began in the fourth quarter 2014 . energy efficiency revenues are largely offset by costs included in other operation and maintenance expenses and have a minimal effect on net income ; and 2022 an annual net rate increase at entergy mississippi of $ 16 million , effective february 2015 , as a result of the mpsc order in the june 2014 rate case . see note 2 to the financial statements for a discussion of rate and regulatory proceedings . the volume/weather variance is primarily due to an increase of 1402 gwh , or 1% ( 1 % ) , in billed electricity usage , including an increase in industrial usage and the effect of more favorable weather . the increase in industrial sales was primarily due to expansion in the chemicals industry and the addition of new customers , partially offset by decreased demand primarily due to extended maintenance outages for existing chemicals customers . 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 an agreement with the lpsc , 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 ) . see note 2 to the financial statements for further discussion of the business combination and customer credits. .