original terms and conditions.
The 2006 Plan awards may be stock options, stock appreciation rights, restricted stock, restricted stock units, performance shares, performance share units, cash-based awards, and other stock-based awards.
A summary of nonvested shares as of December 31, 2007, and changes during the year ended December 31, 2007, under the 1998 Plan and the 2006 Plan is presented below:
## Table 0 ##
(a) Includes performance share units (share units) granted to certain executive and nonexecutive officers and other eligible employees in February 2007 under the 2006 Plan.
(b) Share units vested due to attainment of retirement eligibility by certain employees.
Actual shares issued for retirement-eligible employees will vary depending on actual performance over the three-year measurement period.
Ameren recorded compensation expense of $18 million, $11 million, and $6 million for the years ended December 31, 2007, 2006, and 2005, respectively, and a related tax benefit of $7 million, $4 million, and $2 million for the years ended December 31, 2007, 2006, and 2005, respectively.
As of December 31, 2007, total compensation cost of $20 million related to nonvested awards not yet recognized is expected to be recognized over a weighted-average period of three years.
Performance Share Units A share unit will vest and entitle an employee to receive shares of Ameren common stock (plus accumulated dividends) if, at the end of the three-year performance period, Ameren has achieved certain performance goals and the individual remains employed by Ameren.
The exact number of shares issued pursuant to a share unit will vary from 0% to 200% of the target award, depending on actual company performance relative to the performance goals.
If a share unit vests, Ameren will issue the related shares to the employee two years after vesting, but dividends on the shares will be paid to the employee at the same time they are paid to other shareholders.
The fair value of each share unit awarded in February 2007 under the 2006 Plan was determined to be $59.60, based on Ameren’s closing common share price of $53.99 per share at the grant date and lattice simulations used to estimate expected share payout based on Ameren’s attainment of certain financial measures relative to the designated peer group.
The significant assumptions used to calculate fair value also included a three-year risk-free rate of 4.735%, dividend yields of 2.3% to 5.2% for the peer group, volatility of 12.91% to 18.33% for the peer group, and Ameren’s maintenance of its $2.54 annual dividend over the performance period.
The fair value of each share unit awarded in February 2006 under the 1998 Plan was determined to be $56.07, based on Ameren’s closing common share price of $50.69 per share at the grant date and lattice simulations used to estimate expected share payout based on Ameren’s attainment of certain financial measures relative to the designated peer group.
The significant assumptions used to calculate fair value also included a three-year risk-free rate of 4.65%, dividend yields of 2.3% to 4.6% for the peer group, volatility of 13.87% to 22.45% for the peer group, and Ameren’s maintenance of its $2.54 annual dividend over the performance period.
The fair value of each share unit granted in May 2006 under the 2006 Plan was determined to be $56.07, according to assumptions similar to those applied to the February 2006 grant.
Restricted Stock Restricted stock awards in Ameren common stock were granted under the 1998 Plan from 2001 to 2005.
Restricted shares have the potential to vest over a seven-year period from the date of grant if the company achieves certain performance levels.
An accelerated vesting provision included in this plan reduces the vesting period from seven years to three years if the earnings growth rate exceeds a prescribed level.
During 2005, 154,086 restricted stock awards were granted.
The weighted-average fair value for restricted stock awards granted was $51.21 per share in 2005.
We record compensation expense over the vesting period.
Stock Options Ameren Options in Ameren common stock were granted under the 1998 Plan at a price not less than the fair-market value of the common shares at the date of grant.
Granted options vest over a period of five years, beginning at the date of grant, and they permit accelerated exercising upon the occurrence of certain events, including retirement.
There have not been any stock options granted since December 31, 2000.
Outstanding options of 89,987 at December 31, 2007, expire on various dates through 2010.
There is no expense
Margins The following table presents the favorable (unfavorable) variations in the registrants’ electric and gas margins from the previous year.
Electric margins are defined as electric revenues less fuel and purchased power costs.
Gas margins are defined as gas revenues less gas purchased for resale.
The table covers the years ended December 31, 2007, 2006, and 2005.
We consider electric, interchange and gas margins useful measures to analyze the change in profitability of our electric and gas operations between periods.
We have included the analysis below as a complement to the financial information we provide in accordance with GAAP.
However, these margins may not be a presentation defined under GAAP, and they may not be comparable to other companies’ presentations or more useful than the GAAP information we provide elsewhere in this report.
## Table 1 ##
2006 versus 2005
## Table 2 ##
Ameren Illinois’ cash used in investing activities increased by $152 million during 2017, compared with 2016, because of increased capital expenditures, primarily related to electric transmission system reliability projects and natural gas infrastructure projects.2016 versus 2015 Ameren’s cash used in investing activities associated with continuing operations increased by $190 million during 2016, compared with 2015.
Capital expenditures increased $159 million, primarily because of increased transmission expenditures, which included a $41 million increase at ATXI primarily related to the Illinois Rivers project, and increased Ameren Missouri and Ameren Illinois capital expenditures.
During 2016, there was no cash used in investing activities associated with discontinued operations.
During 2015, Ameren’s cash used in investing activities associated with discontinued operations consisted of a $25 million payment for a liability associated with the New AER divestiture.
Ameren Missouri’s cash used in investing activities increased by $210 million during 2016, compared with 2015.
Capital expenditures increased $116 million, primarily related to electric distribution system reliability and energy center projects.
Additionally, there was an increase in net advances to the money pool of $89 million.
Ameren Illinois’ cash used in investing activities increased by $5 million during 2016, compared with 2015, because of increased capital expenditures, primarily related to qualified investments in natural gas infrastructure under the QIP rider, storm restoration costs, and reliability.
Capital Expenditures The following table presents the capital expenditures by the Ameren Companies for the years ended December 31, 2017, 2016, and 2015:
## Table 3 ##
(a) Includes amounts for the elimination of intercompany transfers.
Ameren’s 2017 capital expenditures consisted of expenditures made by its subsidiaries, including ATXI, which spent $289 million primarily on the Illinois Rivers and Spoon River projects.
Ameren Illinois spent $355 million on transmission projects, $153 million on projects that are recovered under the QIP rider, and $123 million on IEIMA projects.
Other capital expenditures were made principally to maintain, upgrade, and improve the reliability of the transmission and distribution systems of Ameren Missouri and Ameren Illinois by investing in substation upgrades, energy center projects, and smart-grid technology.
Additionally, the Ameren Companies invested in various software projects.
Ameren’s 2016 capital expenditures consisted of expenditures made by its subsidiaries, including ATXI, which spent $416 million primarily on the Illinois Rivers project.
Ameren Illinois spent $273 million on transmission projects and $109 million on IEIMA projects.
Other capital expenditures were made principally to maintain, upgrade, and improve the reliability of the transmission and distribution systems of Ameren Missouri and Ameren Illinois as well as to fund various Ameren Missouri energy center upgrades.
Ameren’s 2015 capital expenditures consisted of expenditures made by its subsidiaries, including ATXI, which spent $375 million primarily on the Illinois Rivers project.
Ameren Illinois spent $294 million on transmission projects and $134 million on IEIMA projects.
Other capital expenditures were made principally to maintain, upgrade, and improve the reliability of the transmission and distribution systems of Ameren Missouri and Ameren Illinois as well as to fund various Ameren Missouri energy center upgrades.
Performance Graph The graph below compares the cumulative total shareholder return on PMI's common stock with the cumulative total return for the same period of PMI's Peer Group and the S&P 500 Index.
The graph assumes the investment of $100 as of December 31, 2012, in PMI common stock (at prices quoted on the New York Stock Exchange) and each of the indices as of the market close and reinvestment of dividends on a quarterly basis.
## Table 4 ##
(1) The PMI Peer Group presented in this graph is the same as that used in the prior year, except Reynolds American Inc.  was removed following the completion of its acquisition by British American Tobacco p. l. c.  on July 25, 2017.
The PMI Peer Group was established based on a review of four characteristics: global presence; a focus on consumer products; and net revenues and a market capitalization of a similar size to those of PMI.
The review also considered the primary international tobacco companies.
As a result of this review, the following companies constitute the PMI Peer Group: Altria Group, Inc. , Anheuser-Busch InBev SA/NV, British American Tobacco p. l. c. , The Coca-Cola Company, Colgate-Palmolive Co. , Diageo plc, Heineken N. V. , Imperial Brands PLC, Japan Tobacco Inc. , Johnson & Johnson, Kimberly-Clark Corporation, The Kraft-Heinz Company, McDonald's Corp. , Mondelz International, Inc. , Nestlé S. A. , PepsiCo, Inc. , The Procter & Gamble Company, Roche Holding AG, and Unilever NV and PLC.
Note: Figures are rounded to the nearest $0.10.

<table><tr><td></td><td colspan="2"> Performance Share Units</td><td colspan="2"> Restricted Shares</td></tr><tr><td></td><td> Shares</td><td> Weighted-average   Fair Value Per   Unit</td><td> Shares</td><td> Weighted-average   Fair Value Per   Share</td></tr><tr><td>Nonvested at January 1, 2007</td><td>338,516</td><td>$56.07</td><td>377,776</td><td>$45.79</td></tr><tr><td>Granted<sup>(a)</sup></td><td>357,573</td><td>59.60</td><td>-</td><td>-</td></tr><tr><td>Dividends</td><td>-</td><td>-</td><td>15,224</td><td>51.52</td></tr><tr><td>Forfeitures</td><td>-13,711</td><td>56.64</td><td>-5,841</td><td>46.47</td></tr><tr><td>Vested<sup>(b)</sup></td><td>-12,975</td><td>59.14</td><td>-70,391</td><td>43.84</td></tr><tr><td>Nonvested at December 31, 2007</td><td>669,403</td><td>$57.88</td><td>316,768</td><td>$46.23</td></tr></table>
<table><tr><td> 2007 versus 2006</td><td>Ameren (a)</td><td>UE</td><td>CIPS</td><td>Genco</td><td>CILCORP</td><td>CILCO</td><td>IP</td></tr><tr><td>Electric revenue change:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Effect of weather (estimate)</td><td>$73</td><td>$31</td><td>$16</td><td>$-</td><td>$9</td><td>$9</td><td>$17</td></tr><tr><td>UE electric rate increase</td><td>29</td><td>29</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Storm-related outages (estimate)</td><td>10</td><td>9</td><td>3</td><td>-3</td><td>-</td><td>-</td><td>1</td></tr><tr><td>JDA terminated December 31, 2006</td><td>-</td><td>-196</td><td>-</td><td>-97</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Elimination of CILCO/AERG power supply agreement</td><td>108</td><td>-</td><td>-</td><td>-</td><td>108</td><td>108</td><td>-</td></tr><tr><td>Interchange revenues, excluding estimated weather impact of -$47 million</td><td>252</td><td>252</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Illinois electric settlement agreement, net of reimbursement</td><td>-73</td><td>-</td><td>-11</td><td>-30</td><td>-20</td><td>-20</td><td>-14</td></tr><tr><td>FERC-ordered MISO resettlements – March 2007</td><td>17</td><td>-</td><td>-</td><td>12</td><td>4</td><td>4</td><td>-</td></tr><tr><td>Mark-to-market losses on energy contracts</td><td>-21</td><td>-13</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Illinois rate redesign, generation repricing, growth and other (estimate)</td><td>287</td><td>11</td><td>36</td><td>-2</td><td>160</td><td>160</td><td>-49</td></tr><tr><td>Total electric revenue change</td><td>$682</td><td>$123</td><td>$44</td><td>$-120</td><td>$261</td><td>$261</td><td>$-45</td></tr><tr><td>Fuel and purchased power change:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Fuel:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Generation and other</td><td>$-35</td><td>$-10</td><td>$-</td><td>$-48</td><td>$22</td><td>$21</td><td>$-</td></tr><tr><td>Emission allowance sales (costs)</td><td>-38</td><td>-29</td><td>-</td><td>-</td><td>14</td><td>11</td><td>-</td></tr><tr><td>Mark-to-market gains (losses) on fuel contracts</td><td>23</td><td>9</td><td>-</td><td>6</td><td>1</td><td>1</td><td>-</td></tr><tr><td>Price</td><td>-98</td><td>-84</td><td>-</td><td>-5</td><td>-5</td><td>-5</td><td>-</td></tr><tr><td>JDA terminated December 31, 2006</td><td>-</td><td>97</td><td>-</td><td>196</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Purchased power</td><td>-90</td><td>-25</td><td>-48</td><td>101</td><td>-120</td><td>-119</td><td>35</td></tr><tr><td>Entergy Arkansas, Inc. power purchase agreement</td><td>-12</td><td>-12</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Elimination of CILCO/AERG power supply agreement</td><td>-108</td><td>-</td><td>-</td><td>-</td><td>-108</td><td>-108</td><td>-</td></tr><tr><td>Insurance recovery</td><td>8</td><td>20</td><td>-</td><td>2</td><td>7</td><td>7</td><td>-</td></tr><tr><td>FERC-ordered MISO resettlements – March 2007</td><td>-35</td><td>-11</td><td>-8</td><td>-</td><td>-4</td><td>-4</td><td>-12</td></tr><tr><td>Storm-related energy costs (estimate)</td><td>-1</td><td>-2</td><td>-</td><td>1</td><td>-</td><td>-</td><td>1</td></tr><tr><td>Total fuel and purchased power change</td><td>$-386</td><td>$-47</td><td>$-56</td><td>$253</td><td>$-193</td><td>$-196</td><td>$24</td></tr><tr><td>Net change in electric margins</td><td>$296</td><td>$76</td><td>$-12</td><td>$133</td><td>$68</td><td>$65</td><td>$-21</td></tr><tr><td>Net change in gas margins</td><td>$15</td><td>$10</td><td>$2</td><td>$-</td><td>$5</td><td>$5</td><td>$1</td></tr></table>
<table><tr><td> 2006 versus 2005</td><td>Ameren (a)</td><td>UE</td><td>CIPS</td><td>Genco</td><td>CILCORP</td><td>CILCO</td><td>IP</td></tr><tr><td>Electric revenue change:</td><td></td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Effect of weather on native load (estimate)</td><td>$-82</td><td>$-39</td><td>$-16</td><td>$-</td><td>$-10</td><td>$-10</td><td>$-17</td></tr><tr><td>Storm-related outages (estimate)</td><td>-10</td><td>-9</td><td>-3</td><td>3</td><td>-</td><td>-</td><td>-1</td></tr><tr><td>Noranda</td><td>46</td><td>46</td><td>-</td><td>-</td><td>-</td><td>-</td><td>-</td></tr><tr><td>UE Illinois service territory transfer to CIPS</td><td>-</td><td>-38</td><td>41</td><td>34</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Wholesale contracts</td><td>-76</td><td>-</td><td>-</td><td>-76</td><td>-</td><td>-</td><td>-</td></tr><tr><td>Interchange revenues<sup>(b)</sup></td><td>236</td><td>-26</td><td>-34</td><td>-46</td><td>8</td><td>8</td><td>-</td></tr><tr><td>Transmission service and other revenues</td><td>-32</td><td>-4</td><td>3</td><td>2</td><td>2</td><td>2</td><td>-12</td></tr><tr><td>Growth and other (estimate)</td><td>72</td><td>27</td><td>27</td><td>40</td><td>12</td><td>12</td><td>67</td></tr><tr><td>Total electric revenue change</td><td>$154</td><td>$-43</td><td>$18</td><td>$-43</td><td>$12</td><td>$12</td><td>$37</td></tr></table>
<table><tr><td></td><td>2017</td><td>2016</td><td>2015</td></tr><tr><td>Ameren Missouri</td><td>$773</td><td>$738</td><td>$622</td></tr><tr><td>Ameren Illinois Electric Distribution</td><td>476</td><td>470</td><td>491</td></tr><tr><td>Ameren Illinois Natural Gas</td><td>245</td><td>181</td><td>133</td></tr><tr><td>Ameren Illinois Transmission</td><td>355</td><td>273</td><td>294</td></tr><tr><td>ATXI</td><td>289</td><td>416</td><td>375</td></tr><tr><td>Other<sup>(a)</sup></td><td>-6</td><td>-2</td><td>2</td></tr><tr><td>Ameren</td><td>$2,132</td><td>$2,076</td><td>$1,917</td></tr></table>
<table><tr><td>Date</td><td>PMI</td><td>PMI Peer Group<sup>-1</sup></td><td>S&P 500 Index</td></tr><tr><td>December 31, 2012</td><td>$100.00</td><td>$100.00</td><td>$100.00</td></tr><tr><td>December 31, 2013</td><td>$108.50</td><td>$122.80</td><td>$132.40</td></tr><tr><td>December 31, 2014</td><td>$106.20</td><td>$132.50</td><td>$150.50</td></tr><tr><td>December 31, 2015</td><td>$120.40</td><td>$143.50</td><td>$152.60</td></tr><tr><td>December 31, 2016</td><td>$130.80</td><td>$145.60</td><td>$170.80</td></tr><tr><td>December 31, 2017</td><td>$156.80</td><td>$172.70</td><td>$208.10</td></tr></table>

Question: What's the total amount of the Ameren (a) in the years where Total electric revenue change is greater than 100?
Answer: 154