what was the average upward revisions of cash flow of previous quantity estimates during the three year period , in millions?
Important information:
text_0: supplementary information on oil and gas producing activities ( unaudited ) c o n t i n u e d summary of changes in standardized measure of discounted future net cash flows relating to proved oil and gas reserves ( in millions ) 2006 2005 2004 sales and transfers of oil and gas produced , net of production , transportation and administrative costs $ ( 5312 ) $ ( 3754 ) $ ( 2689 ) net changes in prices and production , transportation and administrative costs related to future production ( 1342 ) 6648 771 .
table_6: ( in millions ) the revisions of previous quantity estimates of 2006 is 1319 ; the revisions of previous quantity estimates of 2005 is 820 ; the revisions of previous quantity estimates of 2004 is 948 ;
table_13: ( in millions ) the end of year of 2006 is $ 8518 ; the end of year of 2005 is $ 10601 ; the end of year of 2004 is $ 6415 ;
Reasoning Steps:
Step: average1-1(revisions of previous quantity estimates, none) = 1029
Program:
table_average(revisions of previous quantity estimates, none)
Program (Nested):
table_average(revisions of previous quantity estimates, 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 ) c o n t i n u e d summary of changes in standardized measure of discounted future net cash flows relating to proved oil and gas reserves ( in millions ) 2006 2005 2004 sales and transfers of oil and gas produced , net of production , transportation and administrative costs $ ( 5312 ) $ ( 3754 ) $ ( 2689 ) net changes in prices and production , transportation and administrative costs related to future production ( 1342 ) 6648 771 .
Table
( in millions )                                                                                           | 2006             | 2005             | 2004            
sales and transfers of oil and gas produced net of production transportation and administrative costs     | $ -5312 ( 5312 ) | $ -3754 ( 3754 ) | $ -2689 ( 2689 )
net changes in prices and production transportation and administrative costs related to future production | -1342 ( 1342 )   | 6648             | 771             
extensions discoveries and improved recovery less related costs                                           | 1290             | 700              | 1349            
development costs incurred during the period                                                              | 1251             | 1030             | 609             
changes in estimated future development costs                                                             | -527 ( 527 )     | -552 ( 552 )     | -628 ( 628 )    
revisions of previous quantity estimates                                                                  | 1319             | 820              | 948             
net changes in purchases and sales of minerals in place                                                   | 30               | 4557             | 33              
accretion of discount                                                                                     | 1882             | 1124             | 757             
net change in income taxes                                                                                | -660 ( 660 )     | -6694 ( 6694 )   | -627 ( 627 )    
timing and other                                                                                          | -14 ( 14 )       | 307              | 97              
net change for the year                                                                                   | -2083 ( 2083 )   | 4186             | 620             
beginning of year                                                                                         | 10601            | 6415             | 5795            
end of year                                                                                               | $ 8518           | $ 10601          | $ 6415          
net change for the year from discontinued operations                                                      | $ -216 ( 216 )   | $ 162            | $ -152 ( 152 )  
.
Question: 
what was the average upward revisions of cash flow of previous quantity estimates during the three year period , in millions?
Important information:
text_0: supplementary information on oil and gas producing activities ( unaudited ) c o n t i n u e d summary of changes in standardized measure of discounted future net cash flows relating to proved oil and gas reserves ( in millions ) 2006 2005 2004 sales and transfers of oil and gas produced , net of production , transportation and administrative costs $ ( 5312 ) $ ( 3754 ) $ ( 2689 ) net changes in prices and production , transportation and administrative costs related to future production ( 1342 ) 6648 771 .
table_6: ( in millions ) the revisions of previous quantity estimates of 2006 is 1319 ; the revisions of previous quantity estimates of 2005 is 820 ; the revisions of previous quantity estimates of 2004 is 948 ;
table_13: ( in millions ) the end of year of 2006 is $ 8518 ; the end of year of 2005 is $ 10601 ; the end of year of 2004 is $ 6415 ;
Reasoning Steps:
Step: average1-1(revisions of previous quantity estimates, none) = 1029
Program:
table_average(revisions of previous quantity estimates, none)
Program (Nested):
table_average(revisions of previous quantity estimates, none)
