the aeronautics segment generally includes fewer programs that have much larger sales and operating results than programs included in the other segments .due to the large number of comparatively smaller programs in the remaining segments , the discussion of the results of operations of those business segments focuses on lines of business within the segment rather than on specific programs .the following tables of financial information and related discussion of the results of operations of our business segments are consistent with the presentation of segment information in note 5 to the financial statements .we have a number of programs that are classified by the u.s .government and cannot be specifically described .the operating results of these classified programs are included in our consolidated and business segment results , and are subjected to the same oversight and internal controls as our other programs .aeronautics our aeronautics business segment is engaged in the research , design , development , manufacture , integration , sustainment , support , and upgrade of advanced military aircraft , including combat and air mobility aircraft , unmanned air vehicles , and related technologies .key combat aircraft programs include the f-35 lightning ii , f-16 fighting falcon , and f-22 raptor fighter aircraft .key air mobility programs include the c-130j super hercules and the c-5m super galaxy .aeronautics provides logistics support , sustainment , and upgrade modification services for its aircraft .aeronautics 2019 operating results included the following : ( in millions ) 2010 2009 2008 .
[['( in millions )', '2010', '2009', '2008'], ['net sales', '$ 13235', '$ 12201', '$ 11473'], ['operating profit', '1502', '1577', '1433'], ['operating margin', '11.3% ( 11.3 % )', '12.9% ( 12.9 % )', '12.5% ( 12.5 % )'], ['backlog at year-end', '27500', '26700', '27200']]
net sales for aeronautics increased by 8% ( 8 % ) in 2010 compared to 2009 .sales increased in all three lines of business during the year .the $ 800 million increase in air mobility primarily was attributable to higher volume on c-130 programs , including deliveries and support activities , as well as higher volume on the c-5 reliability enhancement and re-engining program ( rerp ) .there were 25 c-130j deliveries in 2010 compared to 16 in 2009 .the $ 179 million increase in combat aircraft principally was due to higher volume on f-35 production contracts , which partially was offset by lower volume on the f-35 sdd contract and a decline in volume on f-16 , f-22 and other combat aircraft programs .there were 20 f-16 deliveries in 2010 compared to 31 in 2009 .the $ 55 million increase in other aeronautics programs mainly was due to higher volume on p-3 and advanced development programs , which partially were offset by a decline in volume on sustainment activities .net sales for aeronautics increased by 6% ( 6 % ) in 2009 compared to 2008 .during the year , sales increased in all three lines of business .the increase of $ 296 million in air mobility 2019s sales primarily was attributable to higher volume on the c-130 programs , including deliveries and support activities .there were 16 c-130j deliveries in 2009 and 12 in 2008 .combat aircraft sales increased $ 316 million principally due to higher volume on the f-35 program and increases in f-16 deliveries , which partially were offset by lower volume on f-22 and other combat aircraft programs .there were 31 f-16 deliveries in 2009 compared to 28 in 2008 .the $ 116 million increase in other aeronautics programs mainly was due to higher volume on p-3 programs and advanced development programs , which partially were offset by declines in sustainment activities .operating profit for the segment decreased by 5% ( 5 % ) in 2010 compared to 2009 .a decline in operating profit in combat aircraft partially was offset by increases in other aeronautics programs and air mobility .the $ 149 million decrease in combat aircraft 2019s operating profit primarily was due to lower volume and a decrease in the level of favorable performance adjustments on the f-22 program , the f-35 sdd contract and f-16 and other combat aircraft programs in 2010 .these decreases more than offset increased operating profit resulting from higher volume and improved performance on f-35 production contracts in 2010 .the $ 35 million increase in other aeronautics programs mainly was attributable to higher volume and improved performance on p-3 and advanced development programs as well as an increase in the level of favorable performance adjustments on sustainment activities in 2010 .the $ 19 million increase in air mobility operating profit primarily was due to higher volume and improved performance in 2010 on c-130j support activities , which more than offset a decrease in operating profit due to a lower level of favorable performance adjustments on c-130j deliveries in 2010 .the remaining change in operating profit is attributable to an increase in other income , net between the comparable periods .aeronautics 2019 2010 operating margins have decreased when compared to 2009 .the operating margin decrease reflects the life cycles of our significant programs .specifically , aeronautics is performing more development and initial production work on the f-35 program and is performing less work on more mature programs such as the f-22 and f-16 .development and initial production contracts yield lower profits than mature full rate programs .accordingly , while net sales increased in 2010 relative to 2009 , operating profit decreased and consequently operating margins have declined. .

Question: what is the percentage change in operating income from 2009 to 2010?
Answer: 4.8%