Task: Table-QA (source dataset: FinQA)

Task: 
You are given a table containing structured data and a natural language question referring to the table. Your goal is to analyze the table and provide an accurate and concise answer based on the given data.

Instructions:
1. Understand the Table: Examine the structure, headers, and data in the table. Identify relevant columns and rows related to the question.
2. Interpret the Question: Determine whether the question requires direct retrieval, aggregation, comparison, sorting, filtering, or inference.
3. Extract the Answer: Use logical reasoning and numerical operations (if necessary) to derive the correct response from the table.
4. Format the Answer: No explanation, return the answer in a structured JSON format: {"answer": <answer>}. If the question cannot be answered due to missing or ambiguous data, return a JSON response with {"answer": null}.

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?


pre_text: 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 .
post_text: .
label: 3297.66667
qa: answer: 3298
ann_table_rows: 11
steps: op: average1-1
arg1: net change for the year
arg2: none
res: 3298
program: table_average(net change for the year, none)
gold_inds: 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 ;
exe_ans: 3297.66667
tfidftopn: 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_9: ( in millions ) The net change in income taxes of 2011 is -6676 ( 6676 ) ; The net change in income taxes of 2010 is -4231 ( 4231 ) ; The net change in income taxes of 2009 is -4345 ( 4345 ) ;
program_re: table_average(net change for the year, none)
model_input: 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 ;