interest and penalties with respect to unrecognized tax benefits were $3 million as of each of December 31, 2015 and 2014.
During 2013, the Company recorded a reduction of $14 million to its liability for uncertain tax positions related to a change approved by the IRS for the allocation of interest costs to long term construction contracts at Ingalls.
This change was made on a prospective basis only and did not impact the tax returns filed for years prior to 2013.
The following table summarizes the tax years that are either currently under examination or remain open under the applicable statute of limitations and subject to examination by the major tax jurisdictions in which the Company operates:
## Table 0 ##
Although the Company believes it has adequately provided for all uncertain tax positions, amounts asserted by taxing authorities could be greater than the Company's accrued position.
Accordingly, additional provisions for federal and state income tax related matters could be recorded in the future as revised estimates are made or the underlying matters are effectively settled or otherwise resolved.
Conversely, the Company could settle positions with the tax authorities for amounts lower than have been accrued.
The Company believes that it is reasonably possible that during the next 12 months the Company's liability for uncertain tax positions may decrease by approximately $2 million due to statute of limitation expirations.
The Company recognizes accrued interest and penalties related to uncertain tax positions in income tax expense.
The IRS is currently conducting an examination of Northrop Grumman's consolidated tax returns, of which HII was part, for the years 2007 through the spin-off.
During 2013 the Company entered into the pre-Compliance Assurance Process with the IRS for years 2011 and 2012.
The Company is part of the IRS Compliance Assurance Process program for the 2014, 2015, and 2016 tax years.
Open tax years related to state jurisdictions remain subject to examination.
As of March 31, 2011, the date of the spin-off, the Company's liability for uncertain tax positions was approximately $4 million, net of federal benefit, which related solely to state income tax positions.
Under the terms of the Separation Agreement, Northrop Grumman is obligated to reimburse HII for any settlement liabilities paid by HII to any government authority for tax periods prior to the spin-off, which include state income taxes.
As a result, the Company recorded in other assets a reimbursement receivable of approximately $4 million, net of federal benefit, related to uncertain tax positions for state income taxes as of the date of the spin-off.
In 2014, the statute of limitations expired for the $4 million liability related to state uncertain tax positions as of the spin-off date.
Accordingly, the $4 million liability and the associated reimbursement receivable were written off.
On September 13, 2013, the Treasury Department and the Internal Revenue Service issued final regulations regarding the deduction and capitalization of amounts paid to acquire, produce, improve, or dispose of tangible personal property.
These regulations are generally effective for tax years beginning on or after January 1, 2014.
The application of these regulations did not have a material impact on the Company's consolidated financial statements.
Deferred Income Taxes - Deferred income taxes reflect the net tax effects of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and for income tax purposes.
Such amounts are classified in the consolidated statements of financial position as current or non-current assets or liabilities based upon the classification of the related assets and liabilities.
Equity Compensation Plan Information The following table presents the equity securities available for issuance under our equity compensation plans as of December 31, 2015.
## Table 1 ##
(1) Includes grants made under the Huntington Ingalls Industries, Inc.  2012 Long-Term Incentive Stock Plan (the "2012 Plan"), which was approved by our stockholders on May 2, 2012, and the Huntington Ingalls Industries, Inc.  2011 Long-Term Incentive Stock Plan (the "2011 Plan"), which was approved by the sole stockholder of HII prior to its spin-off from Northrop Grumman Corporation.
Of these shares, 533,397 were subject to stock options and 54,191 were stock rights granted under the 2011 Plan.
In addition, this number includes 35,553 stock rights, 10,279 restricted stock rights, and 790,936 restricted performance stock rights granted under the 2012 Plan, assuming target performance achievement.
(2) This is the weighted average exercise price of the 533,397 outstanding stock options only.
(3) There are no awards made under plans not approved by security holders.
ITEM 13.
CERTAIN RELATIONSHIPS AND RELATED TRANSACTIONS, AND DIRECTOR INDEPENDENCE Information as to certain relationships and related transactions and director independence will be incorporated herein by reference to the Proxy Statement for our 2016 Annual Meeting of Stockholders, to be filed within 120 days after the end of the Company’s fiscal year.
ITEM 14.
PRINCIPAL ACCOUNTANT FEES AND SERVICES Information as to principal accountant fees and services will be incorporated herein by reference to the Proxy Statement for our 2016 Annual Meeting of Stockholders, to be filed within 120 days after the end of the Company’s fiscal year.
LIQUIDITY AND CAPITAL RESOURCES We endeavor to ensure the most efficient conversion of operating results into cash for deployment in operating our businesses and maximizing stockholder value.
We use various financial measures to assist in capital deployment decision making, including net cash provided by operating activities and free cash flow.
We believe these measures are useful to investors in assessing our financial performance.
The following table summarizes key components of cash flow provided by (used in) operating activities:
## Table 2 ##
Cash Flows We discuss below our major operating, investing, and financing activities for each of the three years in the period ended December 31, 2015, as classified on our consolidated statements of cash flows.
Operating Activities 2015 - Cash provided by operating activities was $828 million in 2015, compared to $716 million in 2014.
The favorable change of $112 million in operating cash flow was primarily due to proceeds from the Aon litigation settlement and a change in funding of retiree benefit plans, partially offset by higher payments for income taxes and a change in trade working capital.
The change in trade working capital was primarily driven by accounts receivable and accounts payable due to timing of receipts and payments, respectively.
We expect cash generated from operations in 2016, in combination with our current cash and cash equivalents, as well as existing credit facilities, to be sufficient to service debt, meet contractual obligations, and finance capital expenditures for at least the next 12 months.2014 - Cash provided by operating activities was $716 million in 2014, compared to $236 million in 2013.
The increase of $480 million was due primarily to decreases in accounts receivable and retirement benefit funding.
In 2014, we paid net cash of $161 million for federal and state income taxes.
Investing Activities 2015 - Cash used in investing activities was $141 million in 2015, a decrease of $296 million from 2014.
The favorable change in investing cash flow was driven by the 2014 acquisitions of UPI and SN3, the sale of the Gulfport Composite Center of Excellence in March 2015, and proceeds from the Aon litigation settlement.
For 2016, we expect our capital expenditures for maintenance and sustainment, excluding discretionary projects, to be between two and three percent of annual revenues.
Sales and Service Revenues 2017 - Ingalls revenues, including intersegment sales, increased $31 million, or 1%, in 2017 compared to 2016, primarily driven by higher revenues in amphibious assault ships, partially offset by lower revenues in surface combatants and the Legend class NSC program.
Amphibious assault ships revenues increased as a result of higher volumes on Bougainville (LHA 8) and Fort Lauderdale (LPD 28), partially offset by lower volume on the delivered USS John P.  Murtha (LPD 26) and Portland (LPD 27).
Surface combatants revenues decreased due to lower volumes on the delivered USS John Finn (DDG 113), Ralph Johnson (DDG 114), Frank E.  Petersen Jr.  (DDG 121), Paul Ignatius (DDG 117), and Delbert D.  Black (DDG 119), partially offset by higher volumes on Lenah H.  Sutcliffe Higbee (DDG 123), Jack H.  Lucas (DDG 125), and the extended selected restricted availability contract for USS Ramage (DDG 61).
Revenues on the Legend class NSC program decreased due to lower volume on the delivered USCGC Munro (NSC 6), partially offset by higher volumes on Stone (NSC 9) and Midgett (NSC 8).2016 - Ingalls revenues, including intersegment sales, increased $201 million, or 9%, in 2016 compared to 2015, primarily driven by higher revenues in surface combatants and amphibious assault ships, partially offset by lower revenues in the Legend class NSC program.
Surface combatants revenues increased due to higher volumes on Frank E.  Petersen Jr.  (DDG 121), Lenah H.  Sutcliffe Higbee (DDG 123), and planning yard services, partially offset by lower volume on John Finn (DDG 113) in connection with its delivery in 2016.
The increase in amphibious assault ships revenues was due to higher volumes on Fort Lauderdale (LPD 28), Tripoli (LHA 7), and Bougainville (LHA 8), partially offset by lower volumes on Portland (LPD 27) and USS John P.  Murtha (LPD 26) following its delivery in 2016.
Revenues on the Legend class NSC program decreased due to delivery of USCGC James (NSC 5) in 2015 and lower volume on Munro (NSC 6), partially offset by higher volume on Midgett (NSC 8).
Segment Operating Income 2017 - Ingalls operating income in 2017 was $313 million, compared to income of $321 million in 2016.
The decrease was primarily due to lower risk retirement on the delivered USS John P.  Murtha (LPD 26) and Arleigh Burke class (DDG 51) destroyers, partially offset by higher risk retirement on Tripoli (LHA 7) and Portland (LPD 27).2016 - Ingalls operating income in 2016 was $321 million, compared to income of $379 million in 2015.
The decrease was primarily due to the impact in 2015 of the settlement of the Aon litigation and lower risk retirement on the America class (LHA 6) program, partially offset by higher risk retirement on USS John P.  Murtha (LPD 26), Portland (LPD 27), and Ralph Johnson (DDG 114).
Newport News

Tables referenced above, in order (Table 0 first):
<table><tr><td>Jurisdiction</td><td>Years</td></tr><tr><td>United States</td><td>2007</td><td>-</td><td>2014</td></tr><tr><td>California</td><td>2010</td><td>-</td><td>2014</td></tr><tr><td>Louisiana</td><td>2012</td><td>-</td><td>2014</td></tr><tr><td>Mississippi</td><td>2012</td><td>-</td><td>2014</td></tr><tr><td>Virginia</td><td>2012</td><td>-</td><td>2014</td></tr></table>
<table><tr><td>Plan category</td><td>Number of Securities to be Issued Upon Exercise of Outstanding Options, Warrants and Rights<sup>-1</sup> (a)(b)</td><td>Weighted-Average Exercise Price of Outstanding Options,Warrants and Rights<sup>-2</sup></td><td>Number of Securities Remaining Available for Future Issuance Under Equity Compensation Plans (Excluding SecuritiesReflected in Column (a)) (c)</td></tr><tr><td>Equity compensation plans approved by security holders</td><td>1,424,356</td><td>$33.90</td><td>4,281,952</td></tr><tr><td>Equity compensation plans not approved by security holders<sup>-3</sup></td><td>—</td><td>—</td><td>—</td></tr><tr><td>Total</td><td>1,424,356</td><td>$33.90</td><td>4,281,952</td></tr></table>
<table><tr><td></td><td colspan="3">Year Ended December 31</td><td colspan="2">2015 over 2014</td><td colspan="2">2014 over 2013</td></tr><tr><td>($ in millions)</td><td>2015</td><td>2014</td><td>2013</td><td>Dollars</td><td>Percent</td><td>Dollars</td><td>Percent</td></tr><tr><td>Net earnings (loss)</td><td>$404</td><td>$338</td><td>$261</td><td>$66</td><td>20%</td><td>$77</td><td>30%</td></tr><tr><td>Depreciation and amortization</td><td>188</td><td>205</td><td>235</td><td>-17</td><td>-8%</td><td>-30</td><td>-13%</td></tr><tr><td>Stock-based compensation</td><td>43</td><td>34</td><td>44</td><td>9</td><td>26%</td><td>-10</td><td>-23%</td></tr><tr><td>Excess tax benefit related to stock-based compensation</td><td>-33</td><td>-39</td><td>-24</td><td>6</td><td>15%</td><td>-15</td><td>-63%</td></tr><tr><td>Deferred income taxes</td><td>-15</td><td>-22</td><td>-28</td><td>7</td><td>32%</td><td>6</td><td>21%</td></tr><tr><td>Retiree benefit funding less than (in excess of) expense</td><td>32</td><td>-4</td><td>-86</td><td>36</td><td>900%</td><td>82</td><td>95%</td></tr><tr><td>Insurance proceeds for investing purposes</td><td>-21</td><td>—</td><td>-58</td><td>-21</td><td>—%</td><td>58</td><td>100%</td></tr><tr><td>Impairment of goodwill and intangible assets</td><td>102</td><td>47</td><td>—</td><td>55</td><td>117%</td><td>47</td><td>—%</td></tr><tr><td>Loss on early extinguishment of debt</td><td>44</td><td>37</td><td>—</td><td>7</td><td>19%</td><td>37</td><td>—%</td></tr><tr><td>Trade working capital decrease (increase)</td><td>84</td><td>120</td><td>-108</td><td>-36</td><td>-30%</td><td>228</td><td>211%</td></tr><tr><td>Net cash provided by (used in) operating activities</td><td>$828</td><td>$716</td><td>$236</td><td>$112</td><td>16%</td><td>$480</td><td>203%</td></tr></table>

Question: what portion of the equity compensation plans approved by security holders remains available for future issuance?
Answer: 0.75039
Reasoning program: add(1424356,4281952), divide(4281952,#0)