what was the average net annual change in discounted future net cash flows ( in millions ) for the years 2011 , 2010 , and 2009?
Important information:
text_0: supplementary information on oil and gas producing activities ( unaudited ) changes in the standardized measure of discounted future net cash flows ( in millions ) 2011 2010 2009 .
table_11: ( in millions ) the net change for the year of 2011 is 4648 ; the net change for the year of 2010 is 3625 ; the net change for the year of 2009 is 1620 ;
table_13: ( in millions ) the end of year of 2011 is $ 13928 ; the end of year of 2010 is $ 9280 ; the end of year of 2009 is $ 5655 ;
Reasoning Steps:
Step: average1-1(net change for the year, none) = 3298
Program:
table_average(net change for the year, none)
Program (Nested):
table_average(net change for the year, none)

Please answer the following financial question based on the context provided. Make sure to give the answer in raw number, not in percentage and without any units. If the question asks for percentage the value should be less than 1
Context:
supplementary information on oil and gas producing activities ( unaudited ) changes in the standardized measure of discounted future net cash flows ( in millions ) 2011 2010 2009 .
Table
( in millions )                                                                            | 2011             | 2010             | 2009            
sales and transfers of oil and gas produced net of production and administrative costs     | $ -7922 ( 7922 ) | $ -6330 ( 6330 ) | $ -4876 ( 4876 )
net changes in prices and production and administrative costs related to future production | 12313            | 9843             | 4840            
extensions discoveries and improved recovery less related costs                            | 1454             | 1268             | 1399            
development costs incurred during the period                                               | 1899             | 2546             | 2786            
changes in estimated future development costs                                              | -1349 ( 1349 )   | -2153 ( 2153 )   | -3773 ( 3773 )  
revisions of previous quantity estimates                                                   | 2526             | 1117             | 5110            
net changes in purchases and sales of minerals in place                                    | 233              | -20 ( 20 )       | -159 ( 159 )    
accretion of discount                                                                      | 2040             | 1335             | 787             
net change in income taxes                                                                 | -6676 ( 6676 )   | -4231 ( 4231 )   | -4345 ( 4345 )  
timing and other                                                                           | 130              | 250              | -149 ( 149 )    
net change for the year                                                                    | 4648             | 3625             | 1620            
beginning of the year                                                                      | 9280             | 5655             | 4035            
end of year                                                                                | $ 13928          | $ 9280           | $ 5655          
.
Question: 
what was the average net annual change in discounted future net cash flows ( in millions ) for the years 2011 , 2010 , and 2009?
Important information:
text_0: supplementary information on oil and gas producing activities ( unaudited ) changes in the standardized measure of discounted future net cash flows ( in millions ) 2011 2010 2009 .
table_11: ( in millions ) the net change for the year of 2011 is 4648 ; the net change for the year of 2010 is 3625 ; the net change for the year of 2009 is 1620 ;
table_13: ( in millions ) the end of year of 2011 is $ 13928 ; the end of year of 2010 is $ 9280 ; the end of year of 2009 is $ 5655 ;
Reasoning Steps:
Step: average1-1(net change for the year, none) = 3298
Program:
table_average(net change for the year, none)
Program (Nested):
table_average(net change for the year, none)
