CHARTER COMMUNICATIONS, INC.  AND SUBSIDIARIES NOTES TO CONSOLIDATED FINANCIAL STATEMENTS DECEMBER 31, 2017, 2016 AND 2015 (dollars in millions, except share or per share data or where indicated) Share Repurchases The following represents the Company's purchase of Charter Class A common stock and the effect on the consolidated statements of cash flows during the years ended December 31, 2017, 2016 and 2015.
## Table 0 ##
As of December 31, 2017, Charter had remaining board authority to purchase an additional $1.1 billion of Charter’s Class A common stock and/or Charter Holdings common units.
See Note 19.
The Company also withholds shares of its Class A common stock in payment of income tax withholding owed by employees upon vesting of equity awards as well as exercise costs owed by employees upon exercise of stock options.
At the end of each fiscal year, Charter’s board of directors approved the retirement of the then currently outstanding treasury stock and those shares were retired as of December 31, 2017 and 2016.
The Company accounts for treasury stock using the cost method and includes treasury stock as a component of total shareholders’ equity.
Upon retirement, these treasury shares are allocated between additional paid-in capital and accumulated deficit based on the cost of original issue included in additional paid-in capital.11.
Noncontrolling Interests Noncontrolling interests represents consolidated subsidiaries of which the Company owns less than 100%.
The Company is a holding company whose principal asset is a controlling equity interest in Charter Holdings, the indirect owner of the Company’s cable systems.
Noncontrolling interests on the Company’s balance sheet primarily includes A/N’s equity interests in Charter Holdings, which is comprised of a common ownership interest and a convertible preferred ownership interest.
As of December 31, 2017, A/N held 22.3 million Charter Holdings common units which are exchangeable at any time into either Charter Class A common stock on a one-for-one basis, or, at Charter’s option, cash, based on the then current market price of Charter Class A common stock.
Net income (loss) of Charter Holdings attributable to A/N’s common noncontrolling interest for financial reporting purposes is based on the weighted average effective common ownership interest of approximately 9% and 10% and was $69 million and $129 million for the years ended December 31, 2017 and 2016, respectively.
Charter Holdings distributed $3 million to A/N as a pro rata tax distribution on its common units during the years ended December 31, 2017 and 2016.
Pursuant to the letter agreement discussed in Note 19, Charter Holdings purchased 4.8 million Charter Holdings common units from A/N, at a price per unit of $347.03, or $1.7 billion during the year ended December 31, 2017, and 0.8 million Charter Holdings common units, at a price per unit of $289.83, or $218 million during the year ended December 31, 2016.
The common units purchased during the year ended December 31, 2017 are reflected as a reduction in noncontrolling interest based on net carrying value of approximately $1.2 billion with the remaining $478 million recorded as reduction of additional paid-in-capital, net of $183 million of deferred income taxes.
The common units purchased during the year ended December 31, 2016 are reflected as a reduction in noncontrolling interest based on net carrying value of approximately $187 million with the remaining $31 million recorded as reduction of additional paid-in-capital, net of $12 million of deferred income taxes.
In December 2017 and 2016, A/N exchanged 1.3 million and 1.9 million Charter Holdings common units, respectively, held by A/N for shares of Charter Class A common stock for an aggregate purchase price of $400 million and $537 million, respectively, pursuant to the letter agreement discussed in Note 19.
The common units exchanged had a net carrying value in noncontrolling interest of approximately $298 million and $460 million as of December 31, 2017 and 2016, respectively.
The exchange of A/N common units resulted in a step-up in the tax-basis of the assets of Charter Holdings which is further discussed in Note 17.
NOTE 9—GOODWILL AND OTHER INTANGIBLES, NET Goodwill The following table outlines the activity in the carrying value of the Company’s goodwill, which is all assigned to the Company’s trading and investing segment (dollars in thousands):
## Table 1 ##
Goodwill is evaluated for impairment on an annual basis and when events or changes indicate the carrying value of an asset exceeds its fair value and the loss may not be recoverable.
At December 31, 2013 and 2012, the Company’s trading and investing segment had two reporting units; market making and retail brokerage.
At the end of June 2013, the Company decided to exit its market making business.
Based on this decision in the second quarter of 2013, the Company conducted an interim goodwill impairment test for the market making reporting unit, using the expected sale structure of the market making business.
This structure assumed a shorter period of cash flows related to an order flow arrangement, compared to prior estimates of fair value.
Based on the results of the first step of the goodwill impairment test, the Company determined that the carrying value of the market making reporting unit, including goodwill, exceeded the fair value for that reporting unit as of June 30, 2013.
The Company proceeded to the second step of the goodwill impairment test to measure the amount of goodwill impairment.
As a result of the evaluation, it was determined that the entire carrying amount of goodwill allocated to the market making reporting unit was impaired, and the Company recognized a $142.4 million impairment of goodwill during the second quarter of 2013.
For the year ended December 31, 2013, the Company performed its annual goodwill assessment for the retail brokerage reporting unit, electing to qualitatively assess whether it was more likely than not that the fair value was less than the carrying value.
As a result of this assessment, the Company determined that the first step of the goodwill impairment test was not necessary, and concluded that goodwill was not impaired at December 31, 2013.
At December 31, 2013, goodwill is net of accumulated impairment losses of $142.4 million related to the trading and investing segment and $101.2 million in the balance sheet management segment.
At December 31, 2012, goodwill is net of accumulated impairment losses of $101.2 million in the balance sheet management segment.
Our ability to restructure or refinance our debt will depend on the condition of the capital markets and our financial condition at such time.
Any refinancing of our debt could be at higher interest rates and may require us to comply with more onerous covenants, which could further restrict our business operations.
In addition, any failure to make payments of interest and principal on our outstanding indebtedness on a timely basis would likely result in a reduction of our credit rating, which could harm our ability to incur additional indebtedness.
If our cash flows and available cash are insufficient to meet our debt service obligations, we could face substantial liquidity problems and might be required to dispose of material assets or operations to meet our debt service and other obligations.
We may not be able to consummate those dispositions or to obtain the proceeds that we could realize from them, and these proceeds may not be adequate to meet any debt service obligations then due.
ITEM 1B.
UNRESOLVED STAFF COMMENTS None.
ITEM 2.
PROPERTIES A summary of our significant locations at December 31, 2013 is shown in the following table.
All facilities are leased, except for 165,000 square feet of our office in Alpharetta, Georgia.
Square footage amounts are net of space that has been sublet or part of a facility restructuring.
## Table 2 ##
(1) Includes approximately 25,000 square footage related to G1 Execution Services, LLC.
We entered into a definitive agreement to sell G1 Execution Services, LLC to an affiliate of Susquehanna.
The lease was assigned to Susquehanna upon closing of the sale on February 10, 2014.
All of our facilities are used by either our trading and investing or balance sheet management segments, in addition to the corporate/other category.
All other leased facilities with space of less than 25,000 square feet are not listed by location.
In addition to the significant facilities above, we also lease all 30 E*TRADE branches, ranging in space from approximately 2,500 to 8,000 square feet.
We believe our facilities space is adequate to meet our needs in 2014.
ITEM 3.
LEGAL PROCEEDINGS On October 27, 2000, Ajaxo, Inc.  (“Ajaxo”) filed a complaint in the Superior Court for the State of California, County of Santa Clara.
Ajaxo sought damages and certain non-monetary relief for the Company’s alleged breach of a non-disclosure agreement with Ajaxo pertaining to certain wireless technology that Ajaxo offered the Company as well as damages and other relief against the Company for their alleged misappropriation of Ajaxo’s trade secrets.
Following a jury trial, a judgment was entered in 2003 in favor of Ajaxo against the Company for $1.3 million for breach of the Ajaxo non-disclosure agreement.
Although the jury found in favor of Ajaxo on its claim against the Company for misappropriation of trade secrets, the trial court subsequently denied Ajaxo’s requests for additional damages and relief.
On December 21, 2005, the California Court of Appeal affirmed the above-described award against the Company for breach of the nondisclosure agreement but remanded the case to the trial court for the limited purpose of determining what, if any, additional damages Ajaxo may be entitled to as a result of the jury’s previous finding in favor of Ajaxo on its claim against the Company for misappropriation of trade secrets.
Although the Company paid Ajaxo the full amount due on the above-described judgment, the case was remanded back to the trial court, and on May 30, 2008, a jury returned a
## Table 3 ##
* Percentage not meaningful.
(1) Metrics have been presented to exclude international local market trading for the year ended December 31, 2009.
(2) E*TRADE Financial Tier 1 leverage ratio is Tier 1 capital divided by average total assets for leverage capital purposes for the parent company.
E*TRADE Financial Tier 1 common ratio is Tier 1 capital less elements of Tier 1 capital that are not in the form of common equity, such as trust preferred securities, divided by total risk-weighted assets for the holding company.
The Tier 1 leverage and Tier 1 common ratios are non-GAAP measures as the parent company is not yet held to these regulatory capital requirements and are indications of E*TRADE Financial’s capital adequacy.
See Item 7.
Management’s Discussion and Analysis of Financial Condition and Results of Operations—Liquidity and Capital Resources for a reconciliation of these non-GAAP measures to the comparable GAAP measures.
(3) The Company transitioned from reporting under the OTS reporting requirements to reporting under the OCC reporting requirements in the first quarter of 2012.
The Tier 1 leverage ratio is the OCC Tier 1 leverage ratio at December 31, 2013 and 2012 and the OTS Tier 1 capital ratio at December 31, 2011, 2010 and 2009.
The OTS Tier 1 capital ratio and OCC Tier 1 leverage ratio are both calculated in the same manner using adjusted total assets.
The selected consolidated financial data should be read in conjunction with Item 7.
Management’s Discussion and Analysis of Financial Condition and Results of Operations and Item 8.
Financial Statements and Supplementary Data
individual loan before being modified as a TDR in the discounted cash flow analysis in order to determine that specific loan’s expected impairment.
Specifically, a loan that has a more severe delinquency history prior to modification will have a higher future default rate in the discounted cash flow analysis than a loan that was not as severely delinquent.
For both of the one- to four-family and home equity loan portfolio segments, the premodification delinquency status, the borrower’s current credit score and other credit bureau attributes, in addition to each loan’s individual default experience and credit characteristics, are incorporated into the calculation of the specific allowance.
A specific allowance is established to the extent that the recorded investment exceeds the discounted cash flows of a TDR with a corresponding charge to provision for loan losses.
The specific allowance for these individually impaired loans represents the forecasted losses over the estimated remaining life of the loan, including the economic concession to the borrower.
Effects if Actual Results Differ Historic volatility in the credit markets has substantially increased the complexity and uncertainty involved in estimating the losses inherent in the loan portfolio.
In the current market it is difficult to estimate how potential changes in the quantitative and qualitative factors, including the impact of home equity lines of credit converting from interest only to amortizing loans or requiring borrowers to repay the loan in full at the end of the draw period, might impact the allowance for loan losses.
If our underlying assumptions and judgments prove to be inaccurate, the allowance for loan losses could be insufficient to cover actual losses.
We may be required under such circumstances to further increase the provision for loan losses, which could have an adverse effect on the regulatory capital position and results of operations in future periods.
During the normal course of conducting examinations, our banking regulators, the OCC and Federal Reserve, continue to review our business and practices.
This process is dynamic and ongoing and we cannot be certain that additional changes or actions will not result from their continuing review.
Valuation of Goodwill and Other Intangible Assets Description Goodwill and other intangible assets are evaluated for impairment on an annual basis as of November 30 and in interim periods when events or changes indicate the carrying value may not be recoverable, such as a significant deterioration in the operating environment or a decision to sell or dispose of a reporting unit.
Goodwill and other intangible assets net of amortization were $1.8 billion and $0.2 billion, respectively, at December 31, 2013.
Judgments Goodwill is allocated to reporting units, which are components of the business that are one level below operating segments.
Reporting units are evaluated for impairment individually during the annual assessment.
Estimating the fair value of reporting units and the assets, liabilities and intangible assets of a reporting unit is a subjective process that involves the use of estimates and judgments, particularly related to cash flows, the appropriate discount rates and an applicable control premium.
Management judgment is required to assess whether the carrying value of the reporting unit can be supported by the fair value of the individual reporting unit.
There are various valuation methodologies, such as the market approach or discounted cash flow methods, that may be used to estimate the fair value of reporting units.
In applying these methodologies, we utilize a number of factors, including actual operating results, future business plans, economic projections, and market data.
The following table shows the comparative data for the amount of goodwill allocated to our reporting units (dollars in millions):

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td colspan="6">Year Ended December 31,</td></tr><tr><td></td><td colspan="2">2017</td><td colspan="2">2016</td><td colspan="2">2015</td></tr><tr><td></td><td>Shares</td><td></td><td>$Shares</td><td></td><td>$Shares</td><td></td></tr><tr><td>$Share buybacks</td><td>33,375,878</td><td>$11,570</td><td>5,070,656</td><td>$1,346</td><td>—</td><td>$—</td></tr><tr><td>Income tax withholding</td><td>447,455</td><td>145</td><td>908,066</td><td>216</td><td>177,696</td><td>38</td></tr><tr><td>Exercise cost</td><td>45,023</td><td></td><td>50,503</td><td></td><td>44,541</td><td></td></tr><tr><td></td><td>33,868,356</td><td>$11,715</td><td>6,029,225</td><td>$1,562</td><td>222,237</td><td>$38</td></tr></table>
<table><tr><td></td><td>Trading & Investing</td></tr><tr><td>Balance at December 31, 2011</td><td>$1,934,232</td></tr><tr><td>Activity</td><td>—</td></tr><tr><td>Balance at December 31, 2012</td><td>1,934,232</td></tr><tr><td>Impairment of goodwill</td><td>-142,423</td></tr><tr><td>Balance at December 31, 2013</td><td>$1,791,809</td></tr></table>
<table><tr><td>Location</td><td>Approximate Square Footage</td></tr><tr><td>Alpharetta, Georgia</td><td>254,000</td></tr><tr><td>Jersey City, New Jersey</td><td>107,000</td></tr><tr><td>Arlington, Virginia</td><td>102,000</td></tr><tr><td>Sandy, Utah</td><td>66,000</td></tr><tr><td>Menlo Park, California</td><td>63,000</td></tr><tr><td>New York, New York</td><td>39,000</td></tr><tr><td>Chicago, Illinois<sup>-1</sup></td><td>36,000</td></tr></table>
<table><tr><td></td><td colspan="5">As of or For the Year Ended December 31,</td><td rowspan="2">Variance 2013 vs. 2012</td></tr><tr><td></td><td>2013</td><td>2012</td><td>2011</td><td>2010</td><td>2009</td></tr><tr><td> <i>Customer Activity Metrics:<sup>-1</sup></i></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>DARTs</td><td>150,743</td><td>138,112</td><td>157,475</td><td>150,532</td><td>179,183</td><td>9%</td></tr><tr><td>Average commission per trade</td><td>$11.13</td><td>$11.01</td><td>$11.01</td><td>$11.21</td><td>$11.33</td><td>1%</td></tr><tr><td>Margin receivables (dollars in billions)</td><td>$6.4</td><td>$5.8</td><td>$4.8</td><td>$5.1</td><td>$3.7</td><td>10%</td></tr><tr><td>End of period brokerage accounts</td><td>2,998,059</td><td>2,903,191</td><td>2,783,012</td><td>2,684,311</td><td>2,630,079</td><td>3%</td></tr><tr><td>Net new brokerage accounts</td><td>94,868</td><td>120,179</td><td>98,701</td><td>54,232</td><td>114,273</td><td>-21%</td></tr><tr><td>Brokerage account attrition rate</td><td>8.8%</td><td>9.0%</td><td>10.3%</td><td>12.2%</td><td>13.2%</td><td>*</td></tr><tr><td>Customer assets (dollars in billions)</td><td>$260.8</td><td>$201.2</td><td>$172.4</td><td>$176.2</td><td>$150.5</td><td>30%</td></tr><tr><td>Net new brokerage assets (dollars in billions)</td><td>$10.4</td><td>$10.4</td><td>$9.7</td><td>$8.1</td><td>$7.2</td><td>0%</td></tr><tr><td>Brokerage related cash (dollars in billions)</td><td>$39.7</td><td>$33.9</td><td>$27.7</td><td>$24.5</td><td>$20.4</td><td>17%</td></tr><tr><td> <i>Company Metrics:</i></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Corporate cash (dollars in millions)</td><td>$415.1</td><td>$407.6</td><td>$484.4</td><td>$470.5</td><td>$393.2</td><td>2%</td></tr><tr><td>E*TRADE Financial Tier 1 leverage ratio<sup>-2</sup></td><td>6.7%</td><td>5.5%</td><td>5.7%</td><td>3.6%</td><td>N/A</td><td>1.2%</td></tr><tr><td>E*TRADE Financial Tier 1 common ratio<sup>-2</sup></td><td>13.8%</td><td>10.3%</td><td>9.4%</td><td>4.8%</td><td>N/A</td><td>3.5%</td></tr><tr><td>E*TRADE Bank Tier 1 leverage ratio<sup>-3</sup></td><td>9.5%</td><td>8.7%</td><td>7.8%</td><td>7.3%</td><td>6.7%</td><td>0.8%</td></tr><tr><td>Special mention loan delinquencies (dollars in millions)</td><td>$271.6</td><td>$342.2</td><td>$467.1</td><td>$589.4</td><td>$804.5</td><td>-21%</td></tr><tr><td>Allowance for loan losses (dollars in millions)</td><td>$453.0</td><td>$480.7</td><td>$822.8</td><td>$1,031.2</td><td>$1,182.7</td><td>-6%</td></tr><tr><td>Enterprise net interest spread</td><td>2.33%</td><td>2.39%</td><td>2.79%</td><td>2.91%</td><td>2.72%</td><td>-0.06%</td></tr><tr><td>Enterprise interest-earning assets (average dollars in billions)</td><td>$40.9</td><td>$44.3</td><td>$42.7</td><td>$41.1</td><td>$44.5</td><td>-8%</td></tr><tr><td>Total employees (period end)</td><td>3,009</td><td>2,988</td><td>3,240</td><td>2,962</td><td>3,084</td><td>1%</td></tr></table>

Question: Which year is Average commission per trade the most?
Answer: 2009