Please answer the given financial question based on the context.
Context: entergy mississippi , inc . management 2019s financial discussion and analysis plan to spin off the utility 2019s transmission business see the 201cplan to spin off the utility 2019s transmission business 201d section of entergy corporation and subsidiaries management 2019s financial discussion and analysis for a discussion of this matter , including the planned retirement of debt and preferred securities . results of operations net income 2011 compared to 2010 net income increased $ 23.4 million primarily due to a lower effective income tax rate . 2010 compared to 2009 net income increased $ 6.0 million primarily due to higher net revenue and higher other income , partially offset by higher taxes other than income taxes , higher depreciation and amortization expenses , and higher interest expense . net revenue 2011 compared to 2010 net revenue consists of operating revenues net of : 1 ) fuel , fuel-related expenses , and gas purchased for resale , 2 ) purchased power expenses , and 3 ) other regulatory charges ( credits ) . following is an analysis of the change in net revenue comparing 2011 to 2010 . amount ( in millions ) .
||amount ( in millions )|
|2010 net revenue|$ 555.3|
|volume/weather|-4.5 ( 4.5 )|
|transmission equalization|4.5|
|other|-0.4 ( 0.4 )|
|2011 net revenue|$ 554.9|
the volume/weather variance is primarily due to a decrease of 97 gwh in weather-adjusted usage in the residential and commercial sectors and a decrease in sales volume in the unbilled sales period . the transmission equalization variance is primarily due to the addition in 2011 of transmission investments that are subject to equalization . gross operating revenues and fuel and purchased power expenses gross operating revenues increased primarily due to an increase of $ 57.5 million in gross wholesale revenues due to an increase in sales to affiliated customers , partially offset by a decrease of $ 26.9 million in power management rider revenue . fuel and purchased power expenses increased primarily due to an increase in deferred fuel expense as a result of higher fuel revenues due to higher fuel rates , partially offset by a decrease in the average market prices of natural gas and purchased power. .
Question: what was the ratio of the increase in the net income in 2011 compared to 2010
Answer:
3.9