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:
| balance at january 1 2007                                    | $ 53     |
|:-------------------------------------------------------------|:---------|
| additions based on tax positions related to the current year | 4        |
| additions for tax positions of prior years                   | 24       |
| reductions for tax positions of prior years                  | -6 ( 6 ) |
| settlements                                                  | -5 ( 5 ) |
| balance at december 31 2007                                  | $ 70     |

Question:
what is the net change amount of unrecognized tax benefits during 2007 , ( in millions ) ?


pre_text: notes to consolidated financial statements uncertain tax provisions as described in note 1 , the company adopted fin 48 on january 1 , 2007 .
the effect of adopting fin 48 was not material to the company 2019s financial statements .
the following is a reconciliation of the company 2019s beginning and ending amount of unrecognized tax benefits ( in millions ) . .
post_text: of the amount included in the previous table , $ 57 million of unrecognized tax benefits would impact the effective tax rate if recognized .
aon does not expect the unrecognized tax positions to change significantly over the next twelve months .
the company recognizes interest and penalties related to unrecognized income tax benefits in its provision for income taxes .
aon accrued potential penalties and interest of less than $ 1 million related to unrecognized tax positions during 2007 .
in total , as of december 31 , 2007 , aon has recorded a liability for penalties and interest of $ 1 million and $ 7 million , respectively .
aon and its subsidiaries file income tax returns in the u.s .
federal jurisdiction as well as various state and international jurisdictions .
aon has substantially concluded all u.s .
federal income tax matters for years through 2004 .
the internal revenue service commenced an examination of aon 2019s federal u.s .
income tax returns for 2005 and 2006 in the fourth quarter of 2007 .
material u.s .
state and local income tax jurisdiction examinations have been concluded for years through 2002 .
aon has concluded income tax examinations in its primary international jurisdictions through 2000 .
aon corporation .
label: 17
qa: answer: 17
ann_table_rows: 5
steps: op: minus2-1
arg1: 70
arg2: 53
res: 17
program: subtract(70, 53)
gold_inds: table_5: balance at january 1 2007 the balance at december 31 2007 of $ 53 is $ 70 ;
exe_ans: 17
tfidftopn: text_2: the following is a reconciliation of the company 2019s beginning and ending amount of unrecognized tax benefits ( in millions ) . .
text_4: aon does not expect the unrecognized tax positions to change significantly over the next twelve months .
program_re: subtract(70, 53)
model_input: table_0
balance at january 1 2007 the balance at january 1 2007 of $ 53 is $ 53 ;
table_2
balance at january 1 2007 the additions for tax positions of prior years of $ 53 is 24 ;
table_5
balance at january 1 2007 the balance at december 31 2007 of $ 53 is $ 70 ;