SEGMENT OPERATING RESULTS Basis of Presentation We are aligned into two reportable segments: Ingalls and Newport News.
## Table 0 ##
KEY SEGMENT FINANCIAL MEASURES Sales and Service Revenues Period-to-period sales reflect performance under new and ongoing contracts.
Changes in sales and service revenues are typically expressed in terms of volume.
Unless otherwise described, volume generally refers to increases (or decreases) in reported revenues due to varying production activity levels, delivery rates, or service levels on individual contracts.
Volume changes will typically carry a corresponding income change based on the margin rate for a particular contract.
Segment Operating Income Segment operating income reflects the aggregate performance results of contracts within a segment.
Excluded from this measure are certain costs not directly associated with contract performance, including the FAS/CAS Adjustment and deferred state income taxes.
Changes in segment operating income are typically expressed in terms of volume, as discussed above, or performance.
Performance refers to changes in contract margin rates.
These changes typically relate to profit recognition associated with revisions to EAC that reflect improved (or deteriorated) operating performance on a particular contract.
Operating income changes are accounted for on a cumulative to date basis at the time an EAC change is recorded.
Segment operating income may also be affected by, among other things, contract performance, the effects of workforce stoppages, the effects of natural disasters such as hurricanes, resolution of disputed items with the customer, recovery of insurance proceeds, and other discrete events.
At the completion of a long-term contract, any originally estimated costs not incurred or reserves not fully utilized, such as warranty reserves, could also impact contract earnings.
Where such items have occurred and the effects are material, a separate description is provided.
## Table 1 ##
Sales and Service Revenues 2012 - Ingalls revenues, including intersegment sales, decreased $45 million, or 2%, in 2012 compared to 2011, as a result of lower sales volumes in Amphibious Assault Ships, partially offset by higher sales volumes in the Legendclass NSC program.
The decrease in Amphibious Assault Ships revenues was due to lower sales following the deliveries of LPD-23 Anchorage and LPD-24 Arlington in 2012 and following the delivery of LPD-22 USS San Diego in 2011, partially offset by higher sales volume on LHA-7 Tripoli, LPD-27 (unnamed), LPD-26 John P.  Murtha and LPD-25 Somerset.
The increase in revenues on the Legend-class NSC program was the result of higher sales volume on the construction of NSC-4 Hamilton and NSC-5 Joshua James and the advance procurement contract on NSC-6 (unnamed), partially offset by lower sales resulting from the delivery of NSC-3 USCGC Stratton in 2011.
Surface Combatants revenues remained stable as higher sales on the DDG-51 Arleigh Burke-class destroyer construction program, driven by higher sales on DDG-114 Ralph Johnson partially offset by lower sales on DDG-110 USS William P.  Lawrence delivered in 2011, as well as higher sales on the DDG-1000 Zumwalt-class destroyer program were offset by lower revenues in Surface Combatants support services.2011 - Ingalls revenues decreased $142 million, or 5%, in 2011 compared to 2010.
The decrease was primarily driven by lower revenues in Surface Combatants, partially offset by higher revenues in Amphibious Assault Ships programs and the Legend-class NSC program.
The decrease in Surface Combatants revenues was primarily due to lower revenues on the DDG-51 Arleigh Burke-class destroyer construction program following the delivery of DDG-110 USS William P.  Lawrence in the first quarter of 2011 and DDG-107 USS Gravely in the third quarter of 2010, partially offset by higher revenues on DDG-113 John Finn in 2011.
The increase in Amphibious Assault Ships revenues was due to higher revenues on LPD-26 John P.  Murtha and the LHA-6 America-class program, partially offset by lower revenues on LPD-22 USS San Diego and LPD-24 Arlington.
The increased revenue on the Legendclass NSC program was primarily due to higher revenues on NSC-4 Hamilton, for which the contract was awarded in the fourth quarter of 2010, partially offset by lower revenues on NSC-3 USCGC Stratton, which was delivered in the third quarter of 2011.
Segment Operating Income 2012 - Ingalls operating income in 2012 was $97 million, compared to a loss of $220 million in 2011.
The increase was primarily due to the absence in 2012 of the goodwill impairment charge recorded in 2011, improved overall performance, and the receipt of $7 million in resolution of a contract dispute with a private party, partially offset by increased workers' compensation expense.2011 - Ingalls operating loss in 2011 was $220 million, compared to a loss of $61 million in 2010.
The higher loss was primarily the result of the 2011 goodwill impairment charge previously described, partially offset by the $113 million pre-tax charge in 2010 resulting from our decision to wind down military shipbuilding at our Avondale facility.
Newport News
## Table 2 ##
income and franchise tax provisions are allocable to contracts in process and, accordingly, are included in general and administrative expenses.
Deferred income taxes are recorded when revenues and expenses are recognized in different periods for financial statement purposes than for tax return purposes.
Deferred tax asset or liability account balances are calculated at the balance sheet date using current tax laws and rates in effect.
Determinations of the expected realizability of deferred tax assets and the need for any valuation allowances against these deferred tax assets were evaluated based upon the stand-alone tax attributes of the Company, and valuation allowances of $21 million and $18 million were deemed necessary as of December 31, 2012 and 2011, respectively.
Uncertain tax positions meeting the more-likely-than-not recognition threshold, based on the merits of the position, are recognized in the financial statements.
We recognize the amount of tax benefit that is greater than 50% likely to be realized upon ultimate settlement with the related tax authority.
If a tax position does not meet the minimum statutory threshold to avoid payment of penalties, we recognize an expense for the amount of the penalty in the period the tax position is claimed or expected to be claimed in our tax return.
Penalties, if probable and reasonably estimable, are recognized as a component of income tax expense.
We also recognize accrued interest related to uncertain tax positions in income tax expense.
The timing and amount of accrued interest is determined by the applicable tax law associated with an underpayment of income taxes.
See Note 11: Income Taxes.
Under existing GAAP, changes in accruals associated with uncertainties are recorded in earnings in the period they are determined.
Cash and Cash Equivalents - The carrying amounts of cash and cash equivalents approximate fair value due to the short-term nature of these items, having original maturity dates of 90 days or less.
Accounts Receivable - Accounts receivable include amounts billed and currently due from customers, amounts currently due but unbilled, certain estimated contract change amounts, claims or requests for equitable adjustment in negotiation that are probable of recovery, and amounts retained by the customer pending contract completion.
Inventoried Costs - Inventoried costs primarily relate to work in process under contracts that recognize revenues using labor dollars or units of delivery as the basis of the percentage-of-completion calculation.
These costs represent accumulated contract costs less cost of sales, as calculated using the percentage-of-completion method.
Accumulated contract costs include direct production costs, factory and engineering overhead, production tooling costs, and, for government contracts, allowable general and administrative expenses.
According to the provisions of the Company's U. S.  Government contracts, the customer asserts title to, or a security interest in, inventories related to such contracts as a result of contract advances, performance-based payments, and progress payments.
In accordance with industry practice, inventoried costs are classified as a current asset and include amounts related to contracts having production cycles longer than one year.
Inventoried costs also include company owned raw materials, which are stated at the lower of cost or market, generally using the average cost method.
Property, Plant, and Equipment - Depreciable properties owned by the Company are recorded at cost and depreciated over the estimated useful lives of individual assets.
Costs incurred for computer software developed or obtained for internal use are capitalized and amortized over the expected useful life of the software, not to exceed nine years.
Leasehold improvements are amortized over the shorter of their useful lives or the term of the lease.
The remaining assets are depreciated using the straight-line method, with the following lives:

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td colspan="3">Year Ended December 31</td><td colspan="2">2012 over 2011</td><td colspan="2">2011 over 2010</td></tr><tr><td>($ in millions)</td><td>2012</td><td>2011</td><td>2010</td><td>Dollars</td><td>Percent</td><td>Dollars</td><td>Percent</td></tr><tr><td>Sales and Service Revenues</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Ingalls</td><td>$2,840</td><td>$2,885</td><td>$3,027</td><td>$-45</td><td>-2%</td><td>$-142</td><td>-5%</td></tr><tr><td>Newport News</td><td>3,940</td><td>3,766</td><td>3,775</td><td>174</td><td>5%</td><td>-9</td><td>—%</td></tr><tr><td>Intersegment eliminations</td><td>-72</td><td>-76</td><td>-79</td><td>4</td><td>5%</td><td>3</td><td>4%</td></tr><tr><td>Total sales and service revenues</td><td>$6,708</td><td>$6,575</td><td>$6,723</td><td>$133</td><td>2%</td><td>$-148</td><td>-2%</td></tr><tr><td>Operating Income (Loss)</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Ingalls</td><td>$97</td><td>$-220</td><td>$-61</td><td>$317</td><td>144%</td><td>$-159</td><td>-261%</td></tr><tr><td>Newport News</td><td>360</td><td>342</td><td>355</td><td>18</td><td>5%</td><td>-13</td><td>-4%</td></tr><tr><td>Total Segment Operating Income (Loss)</td><td>457</td><td>122</td><td>294</td><td>335</td><td>275%</td><td>-172</td><td>-59%</td></tr><tr><td>Non-segment factors affecting operating income (loss)</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>FAS/CAS Adjustment</td><td>-80</td><td>-23</td><td>-56</td><td>-57</td><td>-248%</td><td>33</td><td>59%</td></tr><tr><td>Deferred state income taxes</td><td>-19</td><td>1</td><td>3</td><td>-20</td><td>-2,000%</td><td>-2</td><td>-67%</td></tr><tr><td>Total operating income (loss)</td><td>$358</td><td>$100</td><td>$241</td><td>$258</td><td>258%</td><td>$-141</td><td>-59%</td></tr></table>
<table><tr><td></td><td colspan="3">Year Ended December 31</td><td colspan="2">2012 over 2011</td><td colspan="2">2011 over 2010</td></tr><tr><td>($ in millions)</td><td>2012</td><td>2011</td><td>2010</td><td>Dollars</td><td>Percent</td><td>Dollars</td><td>Percent</td></tr><tr><td>Sales and service revenues</td><td>$2,840</td><td>$2,885</td><td>$3,027</td><td>$-45</td><td>-2%</td><td>$-142</td><td>-5%</td></tr><tr><td>Segment operating income (loss)</td><td>97</td><td>-220</td><td>-61</td><td>317</td><td>144%</td><td>-159</td><td>-261%</td></tr><tr><td>As a percentage of segment sales</td><td>3.4%</td><td>-7.6%</td><td>-2.0%</td><td>—</td><td></td><td>—</td><td></td></tr></table>
<table><tr><td></td><td colspan="3">Year Ended December 31</td><td colspan="2">2012 over 2011</td><td colspan="2">2011 over 2010</td></tr><tr><td>($ in millions)</td><td>2012</td><td>2011</td><td>2010</td><td>Dollars</td><td>Percent</td><td>Dollars</td><td>Percent</td></tr><tr><td>Sales and service revenues</td><td>$3,940</td><td>$3,766</td><td>$3,775</td><td>$174</td><td>5%</td><td>$-9</td><td>—%</td></tr><tr><td>Segment operating income (loss)</td><td>360</td><td>342</td><td>355</td><td>18</td><td>5%</td><td>-13</td><td>-4%</td></tr><tr><td>As a percentage of segment sales</td><td>9.1%</td><td>9.1%</td><td>9.4%</td><td>—</td><td></td><td>—</td><td></td></tr></table>

Question: wha is the percentage change in the valuation allowance from 2011 to 2012?
Answer: 0.16667
Reasoning program: subtract(21,18), divide(#0,18)