Read the following texts and table with financial data from an S&P 500 earnings report carefully.Based on the question-answer history (if provided), answer the last question. The answer may require mathematical calculation based on the data provided.


entergy arkansas , inc . management's financial discussion and analysis results of operations net income 2004 compared to 2003 net income increased $ 16.2 million due to lower other operation and maintenance expenses , a lower effective income tax rate for 2004 compared to 2003 , and lower interest charges . the increase was partially offset by lower net revenue . 2003 compared to 2002 net income decreased $ 9.6 million due to lower net revenue , higher depreciation and amortization expenses , and a higher effective income tax rate for 2003 compared to 2002 . the decrease was substantially offset by lower other operation and maintenance expenses , higher other income , and lower interest charges . net revenue 2004 compared to 2003 net revenue , which is entergy arkansas' measure of gross margin , consists of operating revenues net of : 1 ) fuel , fuel-related , and purchased power expenses and 2 ) other regulatory credits . following is an analysis of the change in net revenue comparing 2004 to 2003. . <table class='wikitable'><tr><td>1</td><td>-</td><td>( in millions )</td></tr><tr><td>2</td><td>2003 net revenue</td><td>$ 998.7</td></tr><tr><td>3</td><td>deferred fuel cost revisions</td><td>-16.9 ( 16.9 )</td></tr><tr><td>4</td><td>other</td><td>-3.4 ( 3.4 )</td></tr><tr><td>5</td><td>2004 net revenue</td><td>$ 978.4</td></tr></table> deferred fuel cost revisions includes the difference between the estimated deferred fuel expense and the actual calculation of recoverable fuel expense , which occurs on an annual basis . deferred fuel cost revisions decreased net revenue due to a revised estimate of fuel costs filed for recovery at entergy arkansas in the march 2004 energy cost recovery rider , which reduced net revenue by $ 11.5 million . the remainder of the variance is due to the 2002 energy cost recovery true-up , made in the first quarter of 2003 , which increased net revenue in 2003 . gross operating revenues , fuel and purchased power expenses , and other regulatory credits gross operating revenues increased primarily due to : 2022 an increase of $ 20.7 million in fuel cost recovery revenues due to an increase in the energy cost recovery rider effective april 2004 ( fuel cost recovery revenues are discussed in note 2 to the domestic utility companies and system energy financial statements ) ; 2022 an increase of $ 15.5 million in grand gulf revenues due to an increase in the grand gulf rider effective january 2004 ; 2022 an increase of $ 13.9 million in gross wholesale revenue primarily due to increased sales to affiliated systems ; 2022 an increase of $ 9.5 million due to volume/weather primarily resulting from increased usage during the unbilled sales period , partially offset by the effect of milder weather on billed sales in 2004. .
Question: what was the net revenue in 2004 for entergy arkansas inc.?
Answer: 978.4
Question: and what was it in 2003?
Answer: 998.7
Question: by how much, then, did it change over the year?

-20.3