Financial report context:
2012 ppg annual report and form 10-k 45 costs related to these notes , which totaled $ 17 million , will be amortized to interest expense over the respective terms of the notes . in august 2010 , ppg entered into a three-year credit agreement with several banks and financial institutions ( the "2010 credit agreement" ) which was subsequently terminated in july 2012 . the 2010 credit agreement provided for a $ 1.2 billion unsecured revolving credit facility . in connection with entering into the 2010 credit agreement , the company terminated its 20ac650 million and its $ 1 billion revolving credit facilities that were each set to expire in 2011 . there were no outstanding amounts due under either revolving facility at the times of their termination . the 2010 credit agreement was set to terminate on august 5 , 2013 . ppg 2019s non-u.s . operations have uncommitted lines of credit totaling $ 705 million of which $ 34 million was used as of december 31 , 2012 . these uncommitted lines of credit are subject to cancellation at any time and are generally not subject to any commitment fees . short-term debt outstanding as of december 31 , 2012 and 2011 , was as follows: .

Financial table:
( millions ): other weighted average 2.27% ( 2.27 % ) as of dec . 31 2012 and 3.72% ( 3.72 % ) as of december 31 2011; 2012: $ 39; 2011: $ 33
( millions ): total; 2012: $ 39; 2011: $ 33

Additional report context:
ppg is in compliance with the restrictive covenants under its various credit agreements , loan agreements and indentures . the company 2019s revolving credit agreements include a financial ratio covenant . the covenant requires that the amount of total indebtedness not exceed 60% ( 60 % ) of the company 2019s total capitalization excluding the portion of accumulated other comprehensive income ( loss ) related to pensions and other postretirement benefit adjustments . as of december 31 , 2012 , total indebtedness was 42% ( 42 % ) of the company 2019s total capitalization excluding the portion of accumulated other comprehensive income ( loss ) related to pensions and other postretirement benefit adjustments . additionally , substantially all of the company 2019s debt agreements contain customary cross- default provisions . those provisions generally provide that a default on a debt service payment of $ 10 million or more for longer than the grace period provided ( usually 10 days ) under one agreement may result in an event of default under other agreements . none of the company 2019s primary debt obligations are secured or guaranteed by the company 2019s affiliates . interest payments in 2012 , 2011 and 2010 totaled $ 219 million , $ 212 million and $ 189 million , respectively . in october 2009 , the company entered into an agreement with a counterparty to repurchase up to 1.2 million shares of the company 2019s stock of which 1.1 million shares were purchased in the open market ( 465006 of these shares were purchased as of december 31 , 2009 at a weighted average price of $ 56.66 per share ) . the counterparty held the shares until september of 2010 when the company paid $ 65 million and took possession of these shares . rental expense for operating leases was $ 233 million , $ 249 million and $ 233 million in 2012 , 2011 and 2010 , respectively . the primary leased assets include paint stores , transportation equipment , warehouses and other distribution facilities , and office space , including the company 2019s corporate headquarters located in pittsburgh , pa . minimum lease commitments for operating leases that have initial or remaining lease terms in excess of one year as of december 31 , 2012 , are ( in millions ) $ 171 in 2013 , $ 135 in 2014 , $ 107 in 2015 , $ 83 in 2016 , $ 64 in 2017 and $ 135 thereafter . the company had outstanding letters of credit and surety bonds of $ 119 million as of december 31 , 2012 . the letters of credit secure the company 2019s performance to third parties under certain self-insurance programs and other commitments made in the ordinary course of business . as of december 31 , 2012 and 2011 , guarantees outstanding were $ 96 million and $ 90 million , respectively . the guarantees relate primarily to debt of certain entities in which ppg has an ownership interest and selected customers of certain of the company 2019s businesses . a portion of such debt is secured by the assets of the related entities . the carrying values of these guarantees were $ 11 million and $ 13 million as of december 31 , 2012 and 2011 , respectively , and the fair values were $ 11 million and $ 21 million , as of december 31 , 2012 and 2011 , respectively . the fair value of each guarantee was estimated by comparing the net present value of two hypothetical cash flow streams , one based on ppg 2019s incremental borrowing rate and the other based on the borrower 2019s incremental borrowing rate , as of the effective date of the guarantee . both streams were discounted at a risk free rate of return . the company does not believe any loss related to these letters of credit , surety bonds or guarantees is likely . 9 . fair value measurement the accounting guidance on fair value measurements establishes a hierarchy with three levels of inputs used to determine fair value . level 1 inputs are quoted prices ( unadjusted ) in active markets for identical assets and liabilities , are considered to be the most reliable evidence of fair value , and should be used whenever available . level 2 inputs are observable prices that are not quoted on active exchanges . level 3 inputs are unobservable inputs employed for measuring the fair value of assets or liabilities . table of contents notes to the consolidated financial statements .

Question: as of december 31 , 2012 , how much room does the company have in its restrictive covenant regarding debt to total capitalization?
Answer: 18%