Foreign currency transaction gains (losses) Foreign currency transaction gains (losses) in millions were as follows:
## Table 0 ##
(1) Includes gains of $21 million, $17 million and $247 million on foreign currency derivative contracts for the years ended December 31, 2017, 2016 and 2015, respectively.
The Company recognized net foreign currency transaction gains of $42 million for the year ended December 31, 2017 primarily driven by transactions associated with VAT activity in Mexico, the amortization of frozen embedded derivatives in the Philippines, and appreciation of the Euro in Bulgaria.
These gains were partially offset by unfavorable foreign currency derivatives in Colombia.
The Company recognized net foreign currency transaction losses of $15 million for the year ended December 31, 2016 primarily due to remeasurement losses on intercompany notes, and losses on swaps and options at The AES Corporation.
This loss was partially offset in Argentina, mainly due to the favorable impact of foreign currency derivatives related to government receivables.
The Company recognized net foreign currency transaction gains of $106 million for the year ended December 31, 2015 primarily due to foreign currency derivatives related to government receivables in Argentina and depreciation of the Colombian peso in Colombia.
These gains were partially offset due to decreases in the valuation of intercompany notes at The AES Corporation and unfavorable devaluation of the Chilean peso in Chile.
Income tax expense Income tax expense increased $958 million to $990 million in 2017 as compared to 2016.
The Company's effective tax rates were 128% and 17% for the years ended December 31, 2017 and 2016, respectively.
The net increase in the 2017 effective tax rate was due primarily to expense related to the U. S.  tax reform one-time transition tax and remeasurement of deferred tax assets.
Further, the 2016 rate was impacted by the items described below.
Income tax expense decreased $380 million to $32 million in 2016 as compared to 2015.
The Company's effective tax rates were 17% and 42% for the years ended December 31, 2016 and 2015, respectively.
The net decrease in the 2016 effective tax rate was due, in part, to the 2016 asset impairments in the U. S. , as well as the devaluation of the peso in certain of our Mexican subsidiaries and the release of valuation allowance at certain of our Brazilian subsidiaries.
These favorable items were partially offset by the unfavorable impact of Chilean income tax law reform enacted during the first quarter of 2016.
Further, the 2015 rate was due, in part, to the nondeductible 2015 impairment of goodwill at DP&L and Chilean withholding taxes offset by the release of valuation allowance at certain of our businesses in Brazil, Vietnam and the U. S.  See Note 19—Asset Impairment Expense included in Item 8.
—Financial Statements and Supplementary Data of this Form 10-K for additional information regarding the 2016 U. S.  asset impairments.
See Note 20—Income Taxes included in Item 8.
—Financial Statements and Supplementary Data of this Form 10-K for additional information regarding the 2016 Chilean income tax law reform.
Our effective tax rate reflects the tax effect of significant operations outside the U. S. , which are generally taxed at rates different than the U. S.  statutory rate.
Foreign earnings may be taxed at rates higher than the new U. S.  corporate rate of 21% and a greater portion of our foreign earnings may be subject to current U. S.  taxation under the new tax rules.
A future proportionate change in the composition of income before income taxes from foreign and domestic tax jurisdictions could impact our periodic effective tax rate.
The Company also benefits from reduced tax rates in certain countries as a result of satisfying specific commitments regarding employment and capital investment.
See Note 20—Income Taxes included in Item 8.
—Financial Statements and Supplementary Data of this Form 10-K for additional information regarding these reduced rates.
CITIZENS FINANCIAL GROUP, INC.  MANAGEMENT’S DISCUSSION AND ANALYSIS 53 Net Interest Income The following table presents the major components of net interest income and net interest margin:
## Table 1 ##
(1) During first quarter 2017, student loans were renamed “education” loans.
For further information see Note 1 “Basis of Presentation” to our audited Consolidated Financial Statements in Part II, Item 8 — Financial Statements and Supplementary Data, included in this report.
(2) Interest income and rates on loans include loan fees.
Additionally, $970 million and $1.1 billion of average nonaccrual loans were included in the average loan balances used to determine the average yield on loans for December 2017 and 2016.
(3) Balances are net of certain short-term receivables associated with reverse repurchase agreements.
Interest expense includes the full cost of the repurchase agreements and certain hedging costs.
See “—Analysis of Financial Condition — Derivatives” for further information.
Item 7.
MANAGEMENT’S DISCUSSION AND ANALYSIS OF FINANCIAL CONDITION AND RESULTS OF OPERATIONS - Continued 66 The following table reconciles free cash flow to “Net cash flows from operating activities.
”
## Table 2 ##
During the years ended December 31, 2005, 2004 and 2003, free cash flow was significantly impacted by changes in operating assets and liabilities as shown in the “Net cash flows from operating activities” section of our Consolidated Statements of Cash Flows included herein.
Operating asset and liability balances can fluctuate significantly from period to period and there can be no assurance that free cash flow will not be negatively impacted by material changes in operating assets and liabilities in future periods, since these changes depend upon, among other things, management’s timing of payments and control of inventory levels, and cash receipts.
In addition to fluctuations resulting from changes in operating assets and liabilities, free cash flow can vary significantly from period to period depending upon, among other things, subscriber growth, subscriber revenue, subscriber churn, subscriber acquisition costs including amounts capitalized under our equipment lease programs, operating efficiencies, increases or decreases in purchases of property and equipment and other factors.
SHVERA requires, among other things, that all local broadcast channels delivered by satellite to any particular market be available from a single dish by June 8, 2006.
We currently offer local broadcast channels in 164 markets across the United States.
In 38 of those markets a second dish was previously required to receive some local channels in the market.
While we have subsequently reduced the number of markets where a second dish is necessary, we can not entirely eliminate the second dish necessity in all markets absent full operability of EchoStar X.
In the event EchoStar X experiences any anomalies, satellite capacity limitations could force us to move the local channels in some two dish markets to different satellites, requiring subscribers in those markets to install a second or different dish to continue receiving their local broadcast channels.
We could be forced, in that event, to stop offering local channels in some of those markets altogether.
The transition of all local broadcast channels in a market to a single dish could result in disruptions of service for a substantial number of our customers.
Further, our ability to timely comply with this requirement without incurring significant additional costs is dependent on, among other things, the continued operation of our EchoStar V satellite at the 129 degree orbital location until commencement of commercial operation of EchoStar X.  EchoStar V or EchoStar X anomalies could force us to cease offering local channels by satellite in many markets absent regulatory relief from the single dish obligations.
If impediments to our preferred transition plan arise, it is possible that the costs of compliance with the single dish requirement could exceed $100.0 million.
To the extent subscribers are unwilling for any reason to upgrade to a new dish, our subscriber churn could be negatively impacted.
In addition, we depend on our EchoStar VIII satellite to provide local channels to over 40 markets at least until such time as our EchoStar X satellite has commenced commercial operation.
In the event that EchoStar VIII experienced a total or substantial failure, we could transmit many, but not all, of those channels from other in-orbit satellites.
The potential relocation of some channels, and elimination of others, resulting from failures relating to EchoStar X or EchoStar VIII, could cause a material adverse impact on our business, including, among other things, a reduction in revenues, an increase in operating expenses, a decrease in new subscriber activations and an increase in subscriber churn.
Impacts from our litigation with the networks in Florida, FCC rules governing the delivery of superstations and other factors could cause us to terminate delivery of network channels and superstations to a substantial number of our subscribers, which could cause many of those customers to cancel their subscription to our other services.
In the event the Court of Appeals upholds the Miami District Court’s network litigation injunction, and if we do not reach private settlement agreements with additional stations, we will attempt to assist subscribers in arranging alternative means to receive network channels, including migration to local channels by satellite where available, and free off air antenna offers in other markets.
However, we cannot predict with any degree of certainty how many subscribers
M&T BANK CORPORATION AND SUBSIDIARIES Notes to Financial Statements — (Continued) A summary of stock option activity follows:

<table><tr><td>Years Ended December 31,</td><td>2017</td><td>2016</td><td>2015</td></tr><tr><td>Mexico</td><td>$17</td><td>$-8</td><td>$-6</td></tr><tr><td>Philippines</td><td>15</td><td>12</td><td>8</td></tr><tr><td>Bulgaria</td><td>14</td><td>-8</td><td>3</td></tr><tr><td>Chile</td><td>8</td><td>-9</td><td>-18</td></tr><tr><td>AES Corporation</td><td>3</td><td>-50</td><td>-31</td></tr><tr><td>Argentina</td><td>1</td><td>37</td><td>124</td></tr><tr><td>United Kingdom</td><td>-3</td><td>13</td><td>11</td></tr><tr><td>Colombia</td><td>-23</td><td>-8</td><td>29</td></tr><tr><td>Other</td><td>10</td><td>6</td><td>-14</td></tr><tr><td>Total<sup>-1</sup></td><td>$42</td><td>$-15</td><td>$106</td></tr></table>
<table><tr><td rowspan="2"></td><td colspan="6">Year Ended December 31,</td><td colspan="2"></td></tr><tr><td colspan="3">2017</td><td colspan="3">2016</td><td colspan="2">Change</td></tr><tr><td>(dollars in millions)</td><td>AverageBalances</td><td>Income/Expense</td><td>Yields/Rates</td><td>AverageBalances</td><td>Income/Expense</td><td>Yields/Rates</td><td>AverageBalances</td><td>Yields/Rates</td></tr><tr><td>Assets</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Interest-bearing cash and due from banks and deposits in banks</td><td>$1,807</td><td>$18</td><td>0.96%</td><td>$1,931</td><td>$8</td><td>0.41%</td><td>-$124</td><td>55 bps</td></tr><tr><td>Taxable investment securities</td><td>25,696</td><td>625</td><td>2.43</td><td>24,643</td><td>584</td><td>2.37</td><td>1,053</td><td>6</td></tr><tr><td>Non-taxable investment securities</td><td>7</td><td>—</td><td>2.60</td><td>8</td><td>—</td><td>2.60</td><td>-1</td><td>—</td></tr><tr><td>Total investment securities</td><td>25,703</td><td>625</td><td>2.43</td><td>24,651</td><td>584</td><td>2.37</td><td>1,052</td><td>6</td></tr><tr><td>Commercial</td><td>37,631</td><td>1,334</td><td>3.50</td><td>35,652</td><td>1,136</td><td>3.13</td><td>1,979</td><td>37</td></tr><tr><td>Commercial real estate</td><td>11,178</td><td>402</td><td>3.55</td><td>9,741</td><td>278</td><td>2.81</td><td>1,437</td><td>74</td></tr><tr><td>Leases</td><td>3,437</td><td>86</td><td>2.50</td><td>3,841</td><td>93</td><td>2.41</td><td>-404</td><td>9</td></tr><tr><td>Total commercial loans and leases</td><td>52,246</td><td>1,822</td><td>3.44</td><td>49,234</td><td>1,507</td><td>3.01</td><td>3,012</td><td>43</td></tr><tr><td>Residential mortgages</td><td>16,017</td><td>571</td><td>3.57</td><td>14,005</td><td>504</td><td>3.60</td><td>2,012</td><td>-3</td></tr><tr><td>Home equity loans</td><td>1,610</td><td>91</td><td>5.68</td><td>2,180</td><td>123</td><td>5.64</td><td>-570</td><td>4</td></tr><tr><td>Home equity lines of credit</td><td>13,706</td><td>514</td><td>3.75</td><td>14,402</td><td>457</td><td>3.18</td><td>-696</td><td>57</td></tr><tr><td>Home equity loans serviced by others</td><td>642</td><td>46</td><td>7.09</td><td>867</td><td>62</td><td>7.11</td><td>-225</td><td>-2</td></tr><tr><td>Home equity lines of credit serviced by others</td><td>181</td><td>7</td><td>4.07</td><td>281</td><td>7</td><td>2.41</td><td>-100</td><td>166</td></tr><tr><td>Automobile</td><td>13,491</td><td>442</td><td>3.27</td><td>13,953</td><td>411</td><td>2.94</td><td>-462</td><td>33</td></tr><tr><td>Education<sup>-1</sup></td><td>7,557</td><td>403</td><td>5.33</td><td>5,558</td><td>282</td><td>5.08</td><td>1,999</td><td>25</td></tr><tr><td>Credit cards</td><td>1,725</td><td>185</td><td>10.75</td><td>1,620</td><td>181</td><td>11.22</td><td>105</td><td>-47</td></tr><tr><td>Other retail</td><td>2,117</td><td>168</td><td>7.94</td><td>1,288</td><td>119</td><td>9.23</td><td>829</td><td>-129</td></tr><tr><td>Total retail loans</td><td>57,046</td><td>2,427</td><td>4.25</td><td>54,154</td><td>2,146</td><td>3.96</td><td>2,892</td><td>29</td></tr><tr><td>Total loans and leases<sup>-2</sup></td><td>109,292</td><td>4,249</td><td>3.87</td><td>103,388</td><td>3,653</td><td>3.51</td><td>5,904</td><td>36</td></tr><tr><td>Loans held for sale, at fair value</td><td>490</td><td>18</td><td>3.58</td><td>425</td><td>15</td><td>3.40</td><td>65</td><td>18</td></tr><tr><td>Other loans held for sale</td><td>190</td><td>10</td><td>5.36</td><td>141</td><td>6</td><td>4.55</td><td>49</td><td>81</td></tr><tr><td>Interest-earning assets</td><td>137,482</td><td>4,920</td><td>3.56</td><td>130,536</td><td>4,266</td><td>3.25</td><td>6,946</td><td>31</td></tr><tr><td>Allowance for loan and lease losses</td><td>-1,225</td><td></td><td></td><td>-1,227</td><td></td><td></td><td>2</td><td></td></tr><tr><td>Goodwill</td><td>6,883</td><td></td><td></td><td>6,876</td><td></td><td></td><td>7</td><td></td></tr><tr><td>Other noninterest-earning assets</td><td>6,813</td><td></td><td></td><td>6,998</td><td></td><td></td><td>-185</td><td></td></tr><tr><td>Total noninterest-earning assets</td><td>12,471</td><td></td><td></td><td>12,647</td><td></td><td></td><td>-176</td><td></td></tr><tr><td>Total assets</td><td>$149,953</td><td></td><td></td><td>$143,183</td><td></td><td></td><td>$6,770</td><td></td></tr><tr><td>Liabilities and Stockholders’ Equity</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Checking with interest</td><td>$21,458</td><td>$79</td><td>0.37%</td><td>$19,320</td><td>$34</td><td>0.18%</td><td>$2,138</td><td>19 bps</td></tr><tr><td>Money market accounts</td><td>37,450</td><td>198</td><td>0.53</td><td>37,106</td><td>133</td><td>0.36</td><td>344</td><td>17</td></tr><tr><td>Regular savings</td><td>9,384</td><td>4</td><td>0.04</td><td>8,691</td><td>4</td><td>0.04</td><td>693</td><td>—</td></tr><tr><td>Term deposits</td><td>15,448</td><td>160</td><td>1.04</td><td>12,696</td><td>99</td><td>0.78</td><td>2,752</td><td>26</td></tr><tr><td>Total interest-bearing deposits</td><td>83,740</td><td>441</td><td>0.53</td><td>77,813</td><td>270</td><td>0.35</td><td>5,927</td><td>18</td></tr><tr><td>Federal funds purchased and securities sold under agreements to repurchase<sup>-3</sup></td><td>776</td><td>3</td><td>0.38</td><td>947</td><td>2</td><td>0.22</td><td>-171</td><td>16</td></tr><tr><td>Other short-term borrowed funds</td><td>2,321</td><td>31</td><td>1.32</td><td>3,207</td><td>40</td><td>1.22</td><td>-886</td><td>10</td></tr><tr><td>Long-term borrowed funds</td><td>12,479</td><td>272</td><td>2.17</td><td>10,472</td><td>196</td><td>1.86</td><td>2,007</td><td>31</td></tr><tr><td>Total borrowed funds</td><td>15,576</td><td>306</td><td>1.96</td><td>14,626</td><td>238</td><td>1.62</td><td>950</td><td>34</td></tr><tr><td>Total interest-bearing liabilities</td><td>99,316</td><td>747</td><td>0.75</td><td>92,439</td><td>508</td><td>0.55</td><td>6,877</td><td>20</td></tr><tr><td>Demand deposits</td><td>28,134</td><td></td><td></td><td>27,634</td><td></td><td></td><td>500</td><td></td></tr><tr><td>Other liabilities</td><td>2,637</td><td></td><td></td><td>3,165</td><td></td><td></td><td>-528</td><td></td></tr><tr><td>Total liabilities</td><td>130,087</td><td></td><td></td><td>123,238</td><td></td><td></td><td>6,849</td><td></td></tr><tr><td>Stockholders’ equity</td><td>19,866</td><td></td><td></td><td>19,945</td><td></td><td></td><td>-79</td><td></td></tr><tr><td>Total liabilities and stockholders’ equity</td><td>$149,953</td><td></td><td></td><td>$143,183</td><td></td><td></td><td>$6,770</td><td></td></tr><tr><td>Interest rate spread</td><td></td><td></td><td>2.81%</td><td></td><td></td><td>2.70%</td><td></td><td>11</td></tr><tr><td>Net interest income</td><td></td><td>$4,173</td><td></td><td></td><td>$3,758</td><td></td><td></td><td></td></tr><tr><td>Net interest margin</td><td></td><td></td><td>3.02%</td><td></td><td></td><td>2.86%</td><td></td><td>16 bps</td></tr><tr><td>Memo: Total deposits (interest-bearing and demand)</td><td>$111,874</td><td>$441</td><td>0.39%</td><td>$105,447</td><td>$270</td><td>0.26%</td><td>$6,427</td><td>13 bps</td></tr></table>
<table><tr><td></td><td colspan="3"> For the Years Ended December 31,</td></tr><tr><td></td><td> 2005</td><td> 2004</td><td> 2003</td></tr><tr><td></td><td colspan="3">(In thousands)</td></tr><tr><td>Free Cash Flow</td><td>$267,680</td><td>$20,855</td><td>$253,762</td></tr><tr><td>Add back:</td><td></td><td></td><td></td></tr><tr><td>Purchases of property and equipment</td><td>1,506,394</td><td>980,587</td><td>321,819</td></tr><tr><td>Net cash flows from operating activities</td><td>$1,774,074</td><td>$1,001,442</td><td>$575,581</td></tr></table>

Question: Which year is Total investment securities for AverageBalances the most?
Answer: 2017