Notes to Consolidated Financial Statements estimation methodologies may have a material effect on the estimated fair value amounts.
We based these fair value estimates on pertinent information available to us as of December 31, 2004 and 2003.
We have not comprehensively updated these fair value estimates for the purposes of these consolidated financial statements since those dates.
Cash Equivalents Cash equivalents consist principally of commercial paper, money market funds, U. S.  government obligations and certificates of deposit with maturities of less than three months when purchased.
The carrying amounts of our cash equivalents approximate their fair values.
Investments Investments in entities in which we have the ability to exercise significant influence over the operating and financial policies of the investee are accounted for under the equity method.
Equity method investments are recorded at original cost and adjusted to recognize our proportionate share of the investees’ net income or losses after the date of investment, amortization of basis differences, additional contributions made and dividends received, and impairment charges resulting from adjustments to net realizable value.
We generally record our proportionate share of our investees’ net income or loss one quarter in arrears given the timing of the receipt of such information.
Changes in our proportionate share of the underlying equity of a consolidated subsidiary or equity method investee that result from the issuance of additional securities by such subsidiary or investee are recognized as gains or losses in our consolidated statement of operations unless gain realization is not assured in the circumstances.
Gains for which realization is not assured are credited directly to additional capital.
Unrestricted publicly traded investments are classified as available for sale or trading securities and are recorded at their fair value.
Unrealized gains or losses resulting from changes in fair value between measurement dates for available for sale securities are recorded as a component of other comprehensive income (loss), except for declines in value that we consider to be other than temporary.
Unrealized gains or losses resulting from changes in fair value between measurement dates for trading securities are recorded as a component of investment income (loss), net.
We recognize realized gains and losses using the specific identification method.
Cash flows from all trading securities are classified as cash flows from operating activities as required by SFAS No.95, “Statement of Cash Flows,” as amended, while cash flows from all other investment securities are classified as cash flows from investing activities in our statement of cash flows.
We review our investment portfolio each reporting period to determine whether a decline in the market value is considered to be other than temporary.
Investments deemed to have experienced an other than temporary decline below their cost basis are reduced to their current fair market value.
The impairment is charged to earnings and a new cost basis for the investment is established.
Restricted publicly traded investments and investments in privately held companies are stated at cost, adjusted for any known decrease in value (see Note 6).
Property and Equipment Depreciation is generally recorded using the straight-line method over estimated useful lives.
The significant components of property and equipment are as follows (dollars in millions):
## Table 0 ##
We capitalize improvements that extend asset lives and expense other repairs and maintenance charges as incurred.
The cost and related accumulated depreciation applicable to assets sold or retired are removed from the accounts and, unless they are presented separately, the gain or loss on disposition is recognized as a component of depreciation expense.
Comcast Corporation Changes in our net deferred tax liability in 2015 that were not recorded as deferred income tax expense are primarily related to decreases of $28 million associated with items included in other comprehensive income (loss) and decreases of $132 million related to acquisitions made in 2015.
Our net deferred tax liability includes $23 billion related to cable franchise rights that will remain unchanged unless we recognize an impairment or dispose of a cable franchise.
As of December 31, 2015, we had federal net operating loss carryforwards of $135 million and various state net operating loss carryforwards that expire in periods through 2035.
As of December 31, 2015, we also had foreign net operating loss carryforwards of $700 million that are related to the foreign operations of NBCUniversal, the majority of which expire in periods through 2025.
The determination of the realization of the state and foreign net operating loss carryforwards is dependent on our subsidiaries’ taxable income or loss, apportionment percentages, and state and foreign laws that can change from year to year and impact the amount of such carryforwards.
We recognize a valuation allowance if we determine it is more likely than not that some portion, or all, of a deferred tax asset will not be realized.
As of December 31, 2015 and 2014, our valuation allowance was primarily related to state and foreign net operating loss carryforwards.
Uncertain Tax Positions Our uncertain tax positions as of December 31, 2015 totaled $1.1 billion, which exclude the federal benefits on state tax positions that were recorded as deferred income taxes.
Included in our uncertain tax positions was $220 million related to tax positions of NBCUniversal and NBCUniversal Enterprise for which we have been indemnified by GE.
If we were to recognize the tax benefit for our uncertain tax positions in the future, $592 million would impact our effective tax rate and the remaining amount would increase our deferred income tax liability.
The amount and timing of the recognition of any such tax benefit is dependent on the completion of examinations of our tax filings by the various tax authorities and the expiration of statutes of limitations.
In 2014, we reduced our accruals for uncertain tax positions and the related accrued interest on these tax positions and, as a result, our income tax expense decreased by $759 million.
It is reasonably possible that certain tax contests could be resolved within the next 12 months that may result in a decrease in our effective tax rate.
Reconciliation of Unrecognized Tax Benefits
## Table 1 ##
As of December 31, 2015 and 2014, our accrued interest associated with tax positions was $510 million and $452 million, respectively.
As of December 31, 2015 and 2014, $49 million and $44 million, respectively, of these amounts were related to tax positions of NBCUniversal and NBCUniversal Enterprise for which we have been indemnified by GE.
During 2015, the IRS completed its examination of our income tax returns for the year 2013.
Various states are examining our tax returns, with most of the periods relating to tax years 2000 and forward.
The tax years of our state tax returns currently under examination vary by state.
Comcast Corporation Note 19: Quarterly Financial Information (Unaudited)
## Table 2 ##
Note 20: Condensed Consolidating Financial Information Comcast (“Comcast Parent”), Comcast Cable Communications, LLC (“CCCL Parent”) and NBCUniversal (“NBCUniversal Media Parent”) have fully and unconditionally guaranteed each other’s debt securities.
In addition, the Comcast revolving credit facility and the Comcast commercial paper program are also fully and unconditionally guaranteed by NBCUniversal.
The Comcast commercial paper program is supported by the Comcast revolving credit facility.
The debt securities within the guarantee structure total $44.3 billion, of which $10.7 billion will mature within the next five years.
In October 2015, we merged three of our wholly owned subsidiaries, Comcast MO Group, LLC (“Comcast MO Group”), Comcast Cable Holdings, LLC (“CCH”) and Comcast MO of Delaware, LLC (“Comcast MO of Delaware”), with and into CCCL Parent.
Comcast MO Group, CCH and Comcast MO of Delaware were guar- antors prior to the merger and were collectively referred to as the “Combined CCHMO Parents.
” Accordingly, the financial information for CCCL Parent reflects both the former Combined CCHMO Parents and the CCCL Parent for all periods presented.
Comcast Parent and CCCL Parent also fully and unconditionally guarantee NBCUniversal Enterprise’s $4 bil- lion of senior notes, as well as the NBCUniversal Enterprise revolving credit facility and the associated commercial paper program.
NBCUniversal Media Parent does not guarantee the NBCUniversal Enterprise senior notes, credit facility or commercial paper program.
Comcast Parent provides an unconditional subordinated guarantee of the $185 million principal amount cur- rently outstanding of Comcast Holdings’ ZONES due October 2029.
Neither CCCL Parent nor NBCUniversal Media Parent guarantee the Comcast Holdings’ ZONES due October 2029.
None of Comcast Parent, CCCL Parent nor NBCUniversal Media Parent guarantee the $62 million principal amount currently outstanding of Comcast Holdings’ ZONES due November 2029 or the $3.3 billion of Universal Studios Japan term loans.
As of December 31, 2015, amounts available under our consolidated revolving credit facilities, net of amounts outstanding under our commercial paper programs and outstanding letters of credit, totaled $6.4 billion, which included $775 million available under the NBCUniversal Enterprise revolving credit facility.
We, NBCUniversal and CCCL Parent are subject to the covenants and restrictions set forth in the indentures governing our public debt securities and in the credit agreements governing the Comcast revolving credit facility.
The only financial covenant is in this credit facility and pertains to leverage, which is the ratio of debt to operating income before depreciation and amortization, as defined in the credit facility.
We test for compliance with the financial covenant for this credit facility on an ongoing basis.
As of December 31, 2015, we met this financial covenant by a significant margin.
We do not expect to have to reduce debt or improve operating results in order to continue to comply with this financial covenant.
In addition, as a result of the acquisition of Universal Studios Japan, we consolidated approximately ￥400 billion (approximately $3.3 billion as of December 31, 2015) in term loans that contain certain financial covenants.
As of December 31, 2015, Universal Studios Japan was in compliance with all of these covenants.
In 2015, we entered into an agreement to establish Atairos Group, Inc. , a new, strategic company focused on investing in and operating growth-oriented companies, both domestically and internationally.
The agreement became effective as of January 1, 2016 and Michael J.  Angelakis, who served as our Chief Financial Officer through June 30, 2015, now serves as the Chairman and Chief Executive Officer of Atairos.
Under the agreement, we are the exclusive non-management investor.
Atairos has a term of up to 12 years.
We are committed to invest up to $4 billion at any one time in the company, subject to certain offsets, and $40 million annually to fund a management fee, subject to certain adjustments.
We will account for our investment in this company under the equity method of accounting.
Operating Activities Components of Net Cash Provided by Operating Activities
## Table 3 ##
The changes in operating assets and liabilities in 2015 compared to the changes in 2014 were primarily related to the timing of film and television production spending and related costs, net of amortization, the timing of payments related to our accounts payable and accrued expenses related to trade creditors and increases in deferred revenue associated with our Olympics broadcasts, partially offset by the timing of collections on our receivables.
The changes in operating assets and liabilities in 2014 compared to the changes in 2013 were primarily due to the timing of film and television production spending and related costs, net of amortization of approximately $600 million.

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td>Useful Life</td><td>December 31, 2004</td><td>December 31, 2003</td></tr><tr><td>Transmission and distribution plant</td><td>2-15 years</td><td>$25,645</td><td>$22,609</td></tr><tr><td>Buildings and building improvements</td><td>2-40 years</td><td>1,365</td><td>1,255</td></tr><tr><td>Land</td><td>N/A</td><td>152</td><td>152</td></tr><tr><td>Other</td><td>3-12 years</td><td>965</td><td>1,020</td></tr><tr><td>Property and equipment, at cost</td><td></td><td>28,127</td><td>25,036</td></tr><tr><td>Less: accumulated depreciation</td><td></td><td>-9,416</td><td>-6,563</td></tr><tr><td>Property and equipment, net</td><td></td><td>$18,711</td><td>$18,473</td></tr></table>
<table><tr><td>(in millions)</td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td>Balance, January 1</td><td>$1,171</td><td>$1,701</td><td>$1,573</td></tr><tr><td>Additions based on tax positions related to the current year</td><td>67</td><td>63</td><td>90</td></tr><tr><td>Additions based on tax positions related to prior years</td><td>98</td><td>111</td><td>201</td></tr><tr><td>Additions from acquired subsidiaries</td><td>—</td><td>—</td><td>268</td></tr><tr><td>Reductions for tax positions of prior years</td><td>-84</td><td>-220</td><td>-141</td></tr><tr><td>Reductions due to expiration of statutes of limitations</td><td>-41</td><td>-448</td><td>-3</td></tr><tr><td>Settlements with tax authorities</td><td>-75</td><td>-36</td><td>-287</td></tr><tr><td>Balance, December 31</td><td>$1,136</td><td>$1,171</td><td>$1,701</td></tr></table>
<table><tr><td>(in millions, except per share data)</td><td>FirstQuarter</td><td>Second Quarter</td><td>Third Quarter</td><td>Fourth Quarter</td><td>TotalYear</td></tr><tr><td> 2015</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td> Revenue</td><td>$17,853</td><td>$18,743</td><td>$18,669</td><td>$19,245</td><td>$74,510</td></tr><tr><td> Operating income</td><td>$3,890</td><td>$4,105</td><td>$4,001</td><td>$4,002</td><td>$15,998</td></tr><tr><td> Net income attributable to Comcast Corporation</td><td>$2,059</td><td>$2,137</td><td>$1,996</td><td>$1,971</td><td>$8,163</td></tr><tr><td> Basic earnings per common share attributable to Comcast Corporation shareholders</td><td>$0.82</td><td>$0.85</td><td>$0.81</td><td>$0.80</td><td>$3.28</td></tr><tr><td> Diluted earnings per common share attributable to Comcast Corporation shareholders</td><td>$0.81</td><td>$0.84</td><td>$0.80</td><td>$0.79</td><td>$3.24</td></tr><tr><td> Dividends declared per common share</td><td>$0.25</td><td>$0.25</td><td>$0.25</td><td>$0.25</td><td>$1.00</td></tr><tr><td>2014</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Revenue</td><td>$17,408</td><td>$16,844</td><td>$16,791</td><td>$17,732</td><td>$68,775</td></tr><tr><td>Operating income</td><td>$3,568</td><td>$3,804</td><td>$3,745</td><td>$3,787</td><td>$14,904</td></tr><tr><td>Net income attributable to Comcast Corporation<sup>(a)</sup></td><td>$1,871</td><td>$1,992</td><td>$2,592</td><td>$1,925</td><td>$8,380</td></tr><tr><td>Basic earnings per common share attributable to Comcast Corporation shareholders</td><td>$0.72</td><td>$0.77</td><td>$1.00</td><td>$0.75</td><td>$3.24</td></tr><tr><td>Diluted earnings per common share attributable to Comcast Corporation shareholders</td><td>$0.71</td><td>$0.76</td><td>$0.99</td><td>$0.74</td><td>$3.20</td></tr><tr><td>Dividends declared per common share</td><td>$0.225</td><td>$0.225</td><td>$0.225</td><td>$0.225</td><td>$0.90</td></tr></table>
<table><tr><td>Year ended December 31 (in millions)</td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td>Operating income</td><td>$15,998</td><td>$14,904</td><td>$13,563</td></tr><tr><td>Depreciation and amortization</td><td>8,680</td><td>8,019</td><td>7,871</td></tr><tr><td>Operating income before depreciation and amortization</td><td>24,678</td><td>22,923</td><td>21,434</td></tr><tr><td>Noncash share-based compensation</td><td>567</td><td>513</td><td>419</td></tr><tr><td>Termination of receivables monetization programs</td><td>—</td><td>—</td><td>-1,442</td></tr><tr><td>Changes in operating assets and liabilities</td><td>-267</td><td>-357</td><td>93</td></tr><tr><td>Cash basis operating income</td><td>24,978</td><td>23,079</td><td>20,504</td></tr><tr><td>Payments of interest</td><td>-2,443</td><td>-2,389</td><td>-2,355</td></tr><tr><td>Payments of income taxes</td><td>-3,726</td><td>-3,668</td><td>-3,946</td></tr><tr><td>Proceeds from investments and other</td><td>251</td><td>190</td><td>162</td></tr><tr><td>Excess tax benefits under share-based compensation</td><td>-282</td><td>-267</td><td>-205</td></tr><tr><td>Net cash provided by operating activities</td><td>$18,778</td><td>$16,945</td><td>$14,160</td></tr></table>

Question: What is the average amount of Balance, December 31 of 2015, and Depreciation and amortization of 2013 ?
Answer: 4503.5
Reasoning program: add(1136.0,7871.0), divide(#0,const_2)