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 .
table: Balance at January 1, 2007 $53
table: Additions based on tax positions related to the current year 4
table: Additions for tax positions of prior years 24
table: Reductions for tax positions of prior years (6)
table: Settlements (5)
table: Balance at December 31, 2007 $70
question: Analyse this data from a financial earnings document. what is the percentual increase in the balance during the year 2007?