(ii) 50 percent of the units awarded will be multiplied by a factor that may range from 0 to 120 percent for management employees and from 0 to 200 percent, based on the Companies’ annual incentive plans or, for certain executive officers, actual performance as compared to certain performance measures during a specified performance period (the non-TSR portion).
Performance RSU awards generally vest upon completion of the performance period.
Performance against the established targets is recomputed each reporting period as of the earlier of the reporting date and the vesting date.
The TSR portion applies a Monte Carlo simulation model, and the non-TSR portion is the product of the market price at the end of the period and the average non-TSR determination over the vesting period.
Performance RSUs are “liability awards” because each Performance RSU represents the right to receive, upon vesting, one share of Con Edison common stock, the cash value of a share or a combination thereof.
As such, changes in the fair value of the Performance RSUs are reflected in net income.
The assumptions used to calculate the fair value of the awards were as follows:
## Table 0 ##
(a) The risk-free rate is based on the U. S.  Treasury zero-coupon yield curve on the date of grant.
(b) The expected term of the Performance RSUs equals the vesting period.
The Companies do not expect significant forfeitures to occur.
(c) The expected volatility is calculated using daily closing stock prices over a period of three years, which approximates the expected term of the awards.
A summary of changes in the status of the Performance RSUs’ TSR and non-TSR portions during the year ended December 31, 2015 is as follows:
## Table 1 ##
(a) The TSR and non-TSR Portions each account for 50 percent of the awards’ value.
(b) Fair value is determined using the Monte Carlo simulation described above.
Weighted average grant date fair value does not reflect any accrual or payment of dividends prior to vesting.
(c) Fair value is determined using the market price of one share of Con Edison common stock on the grant date.
The market price has not been discounted to reflect that dividends do not accrue and are not payable on Performance RSUs until vesting.
The total expense to be recognized by Con Edison in future periods for unvested Performance RSUs outstanding at December 31, 2015 is $29 million, including $23 million for CECONY, and is expected to be recognized over a weighted average period of one year for both Con Edison and CECONY.
In accordance with the accounting rules for stock compensation, for time-based awards, the Companies have accrued a liability based on the market value of a common share on the grant date and are recognizing compensation expense over the vesting period.
The vesting period for awards is three years and is based on the employee’s continuous service to Con Edison.
Prior to vesting, the awards are subject to forfeiture in whole or in part under certain circumstances.
The awards are “liability awards” because each restricted stock unit represents the right to receive, upon vesting, one share of Con Edison common stock, the cash value of a share or a combination thereof.
As such, prior to vesting, changes in the fair value of the units are reflected in net income.
A summary of changes in the status of time-based awards during the year ended December 31, 2015 is as follows:
Other operations and maintenance expenses increased $90 million due primarily to higher costs for the support and protection of company underground facilities to accommodate New York City municipal projects ($25 million), higher costs for injuries and damages ($24 million), an increase in healthcare costs ($12 million) and an increase in the surcharges for assessments and fees that are collected in revenues from customers ($11 million).
Depreciation and amortization increased $32 million due primarily to higher electric utility plant balances.
Taxes, other than income taxes decreased $1 million principally due to a sales and use tax refund, offset in part by higher property taxes.
Gas CECONY’s results of gas operations for the year ended December 31, 2014 compared with the year ended December 31, 2013 is as follows:
## Table 2 ##
CECONY’s gas sales and deliveries, excluding off-system sales, in 2014 compared with 2013 were:
## Table 3 ##
(a) Revenues from gas sales are subject to a weather normalization clause and a revenue decoupling mechanism, as a result of which, delivery revenues are generally not affected by changes in delivery volumes from levels assumed when rates were approved.
(b) After adjusting for variations, principally weather and billing days, firm gas sales and transportation volumes in the company’s service area increased 8.0 percent in 2014 compared with 2013, reflecting primarily higher oil-to-gas conversions and transfers to firm service.
(c) Includes 6,057 and 5,362 thousands of Dt for 2014 and 2013, respectively, which are also reflected in firm transportation and other.
(d) Other gas operating revenues generally reflect changes in regulatory assets and liabilities in accordance with the company’s rate plans.
See Note B to the financial statements in Item 8.
Operating revenues increased $105 million in 2014 compared with 2013 due primarily to an increase in gas purchased for resale expenses ($77 million) and higher revenues from the gas rate plan ($31 million).
Gas purchased for resale increased $77 million in 2014 compared with 2013 due to higher unit costs ($67 million) and sendout volumes ($10 million).
Other operations and maintenance expenses increased $67 million due primarily to higher operating costs attributable to emergency response ($25 million), higher pension costs ($10 million), an increase in the surcharges for assessments and fees that are collected in revenues from customers ($8 million), higher costs for injuries and damages ($4 million) and higher healthcare costs ($2 million).
Depreciation and amortization increased $2 million due primarily to higher gas utility plant balances.
Hologic, Inc.  Notes to Consolidated Financial Statements (continued) (In thousands, except per share data) The acquisition also provided for a one-year earn out of EUR 1,700 (approximately $2,000 USD) which was payable in cash if AEG calendar year 2006 earnings, as defined, exceeded a pre-determined amount.
AEG’s 2006 earnings did not exceed such pre-determined amounts and no payment was made.
The components and allocation of the purchase price, consists of the following approximate amounts:

<table><tr><td></td><td>2015</td><td>2014</td><td>2013</td></tr><tr><td>Risk-free interest rate (a)</td><td>0.64% - 3.28%</td><td>0.23% - 3.07%</td><td>0.13% - 5.17%</td></tr><tr><td>Expected term (b)</td><td>3 years</td><td>3 years</td><td>3 years</td></tr><tr><td>Expected share price volatility (c)</td><td>15.82%</td><td>13.14%</td><td>13.52%</td></tr></table>
<table><tr><td></td><td colspan="3">Con Edison</td><td colspan="3">CECONY</td></tr><tr><td></td><td></td><td colspan="2">Weighted Average Grant Date Fair Value (a)</td><td></td><td colspan="2">Weighted Average Grant Date Fair Value (a)</td></tr><tr><td></td><td>Units</td><td>TSRPortion (b)</td><td>Non-TSRPortion (c)</td><td>Units</td><td>TSRPortion (b)</td><td>Non-TSRPortion (c)</td></tr><tr><td>Non-vested at December 31, 2014</td><td>1,100,607</td><td>$42.33</td><td>$56.61</td><td>880,523</td><td>$42.58</td><td>$56.70</td></tr><tr><td>Granted</td><td>363,900</td><td>57.67</td><td>63.22</td><td>288,669</td><td>57.22</td><td>63.12</td></tr><tr><td>Vested</td><td>-327,536</td><td>49.45</td><td>58.84</td><td>-266,683</td><td>49.34</td><td>58.83</td></tr><tr><td>Forfeited</td><td>-58,632</td><td>43.84</td><td>58.25</td><td>-49,252</td><td>43.54</td><td>58.14</td></tr><tr><td>Non-vested at December 31, 2015</td><td>1,078,339</td><td>$45.26</td><td>$58.08</td><td>853,257</td><td>$45.37</td><td>$58.12</td></tr></table>
<table><tr><td></td><td colspan="2">For the Years Ended December 31,</td><td></td></tr><tr><td>(Millions of Dollars)</td><td>2014</td><td>2013</td><td>Variation</td></tr><tr><td>Operating revenues</td><td>$1,721</td><td>$1,616</td><td>$105</td></tr><tr><td>Gas purchased for resale</td><td>609</td><td>532</td><td>77</td></tr><tr><td>Other operations and maintenance</td><td>418</td><td>351</td><td>67</td></tr><tr><td>Depreciation and amortization</td><td>132</td><td>130</td><td>2</td></tr><tr><td>Taxes, other than income taxes</td><td>248</td><td>241</td><td>7</td></tr><tr><td>Gas operating income</td><td>$314</td><td>$362</td><td>$-48</td></tr></table>
<table><tr><td></td><td colspan="4">Thousands of Dt Delivered</td><td colspan="4">Revenues in Millions (a)</td></tr><tr><td></td><td colspan="2">For the Years Ended</td><td colspan="2"></td><td colspan="2">For the Years Ended</td><td colspan="2"></td></tr><tr><td>Description</td><td>December 31, 2014</td><td>December 31, 2013</td><td>Variation</td><td>PercentVariation</td><td>December 31, 2014</td><td>December 31, 2013</td><td>Variation</td><td>PercentVariation</td></tr><tr><td>Residential</td><td>46,661</td><td>38,872</td><td>7,789</td><td>20.0%</td><td>$782</td><td>$720</td><td>$62</td><td>8.6%</td></tr><tr><td>General</td><td>28,969</td><td>28,135</td><td>834</td><td>3.0</td><td>359</td><td>339</td><td>20</td><td>5.9</td></tr><tr><td>Firm transportation</td><td>68,731</td><td>61,139</td><td>7,592</td><td>12.4</td><td>453</td><td>414</td><td>39</td><td>9.4</td></tr><tr><td>Total firm sales and transportation</td><td>144,361</td><td>128,146</td><td>16,215</td><td>12.7(b)</td><td>1,594</td><td>1,473</td><td>121</td><td>8.2</td></tr><tr><td>Interruptible sales (c)</td><td>10,498</td><td>10,900</td><td>-402</td><td>-3.7</td><td>91</td><td>69</td><td>22</td><td>31.9</td></tr><tr><td>NYPA</td><td>47,548</td><td>48,682</td><td>-1,134</td><td>-2.3</td><td>2</td><td>2</td><td>—</td><td>—</td></tr><tr><td>Generation plants</td><td>82,146</td><td>62,764</td><td>19,382</td><td>30.9</td><td>30</td><td>26</td><td>4</td><td>15.4</td></tr><tr><td>Other</td><td>22,866</td><td>24,615</td><td>-1,749</td><td>-7.1</td><td>40</td><td>45</td><td>-5</td><td>-11.1</td></tr><tr><td>Other operating revenues (d)</td><td>—</td><td>—</td><td>—</td><td>—</td><td>-36</td><td>1</td><td>-37</td><td>Large</td></tr><tr><td>Total</td><td>307,419</td><td>275,107</td><td>32,312</td><td>11.7%</td><td>$1,721</td><td>$1,616</td><td>$105</td><td>6.5%</td></tr></table>

Question: What is the percentage of Gas operating income in relation to the total in 2014 ? (in million)
Answer: 0.18245