page 59 of 94 notes to consolidated financial statements ball corporation and subsidiaries 13 . debt and interest costs ( continued ) long-term debt obligations outstanding at december 31 , 2007 , have maturities of $ 127.1 million , $ 160 million , $ 388.4 million , $ 625.1 million and $ 550.3 million for the years ending december 31 , 2008 through 2012 , respectively , and $ 456.1 million thereafter . ball provides letters of credit in the ordinary course of business to secure liabilities recorded in connection with industrial development revenue bonds and certain self-insurance arrangements . letters of credit outstanding at december 31 , 2007 and 2006 , were $ 41 million and $ 52.4 million , respectively . the notes payable and senior credit facilities are guaranteed on a full , unconditional and joint and several basis by certain of the company 2019s domestic wholly owned subsidiaries . certain foreign denominated tranches of the senior credit facilities are similarly guaranteed by certain of the company 2019s wholly owned foreign subsidiaries . note 22 contains further details as well as condensed , consolidating financial information for the company , segregating the guarantor subsidiaries and non-guarantor subsidiaries . the company was not in default of any loan agreement at december 31 , 2007 , and has met all debt payment obligations . the u.s . note agreements , bank credit agreement and industrial development revenue bond agreements contain certain restrictions relating to dividend payments , share repurchases , investments , financial ratios , guarantees and the incurrence of additional indebtedness . on march 27 , 2006 , ball expanded its senior secured credit facilities with the addition of a $ 500 million term d loan facility due in installments through october 2011 . also on march 27 , 2006 , ball issued at a price of 99.799 percent $ 450 million of 6.625% ( 6.625 % ) senior notes ( effective yield to maturity of 6.65 percent ) due in march 2018 . the proceeds from these financings were used to refinance existing u.s . can debt with ball corporation debt at lower interest rates , acquire certain north american plastic container net assets from alcan and reduce seasonal working capital debt . ( see note 3 for further details of the acquisitions. ) on october 13 , 2005 , ball refinanced its senior secured credit facilities to extend debt maturities at lower interest rate spreads and provide the company with additional borrowing capacity for future growth . during the third and fourth quarters of 2005 , ball redeemed its 7.75% ( 7.75 % ) senior notes due in august 2006 . the refinancing and senior note redemptions resulted in a debt refinancing charge of $ 19.3 million ( $ 12.3 million after tax ) for the related call premium and unamortized debt issuance costs . a summary of total interest cost paid and accrued follows: .

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( $ in millions )	2007	2006	2005
interest costs before refinancing costs	$ 155.8	$ 142.5	$ 102.4
debt refinancing costs	2013	2013	19.3
total interest costs	155.8	142.5	121.7
amounts capitalized	-6.4 ( 6.4 )	-8.1 ( 8.1 )	-5.3 ( 5.3 )
interest expense	$ 149.4	$ 134.4	$ 116.4
interest paid during the year ( a )	$ 153.9	$ 125.4	$ 138.5
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( a ) includes $ 6.6 million paid in 2005 in connection with the redemption of the company 2019s senior and senior subordinated notes. .

Question: what is the percentage change in interest expense from 2005 to 2006?
Program: subtract(134.4, 116.4), divide(#0, 116.4)
Answer: 0.15464