ABIOMED, INC.  AND SUBSIDIARIES Notes to Consolidated Financial Statements—(Continued) Note 8.
Stock Award Plans and Stock Based Compensation (Continued) Restricted Stock The following table summarizes restricted stock activity for the fiscal year ended March 31, 2011:
## Table 0 ##
The remaining unrecognized compensation expense for restricted stock awards at March 31, 2011 was $2.8 million and the weighted-average period over which this cost will be recognized is 2.0 years.
Performance Based Awards Included in the stock option and restricted stock activity discussed above are certain awards granted in fiscal years 2009, 2010 and 2011 that contain performance based vesting.
In August 2008, 406,250 shares of restricted common stock and options to purchase 93,750 shares of common stock were issued to certain executive officers and members of senior management of the Company, all of which would vest upon achievement of certain sales and profitability performance targets in fiscal years 2009 through 2011.
In August 2009, 50,000 additional shares of restricted stock were issued to certain additional executive officers of the Company, which had the same vesting milestones based on fiscal 2010 and 2011 performance targets.
In March 2009, the Company met one of the prescribed performance milestones and a portion of these shares and stock options vested.
During the fiscal years ended March 31, 2010 and 2011, the Company determined that it did not meet any of the prescribed performance targets for fiscal 2010 and 2011.
Accordingly, 333,125 shares of restricted stock related to these awards were forfeited and 76,875 shares underlying stock options related to these awards failed to vest.
There is no remaining compensation expense related to the August 2008 award performance targets as of March 31, 2011.
In June 2010, 311,000 shares of restricted stock and a performance award for the potential issuance of 45,000 shares of common stock were issued to certain executive officers and members of senior management of the Company, all of which could vest upon achievement of prescribed performance milestones.
During the year ended March 31, 2011, the Company determined that it met the prescribed performance targets and a portion of these shares and stock options vested.
As of March 31, 2011, the Company has determined that it is probable it will meet the remaining prescribed performance milestones for both of these awards.
During the year ended March 31, 2011, the Company has recorded $1.0 million in stock-based compensation cost for shares and options in which the prescribed performance milestones have been achieved or are probable of being achieved.
The remaining unrecognized compensation expense related to these shares and options at March 31, 2011 is $2.3 million based on the Company’s current assessment of probability of achieving the performance milestones.
Note 9.
Income Taxes Deferred tax assets and liabilities are recognized for the estimated future tax consequences attributable to tax benefit carryforwards and to differences between the financial statement amounts of assets and liabilities and their respective tax basis.
Deferred tax assets and liabilities are measured using enacted tax rates.
A valuation reserve is established if it is more likely than not that all or a portion of the deferred tax asset will not be realized.
The tax benefit associated with the stock option compensation deductions will be credited to equity when realized.
Capital Requirements and Resources Capital Requirements The following table contains the Companies’ capital requirements for the years 2012 through 2014 and their current estimate of amounts for 2015 through 2017.
## Table 1 ##
(a) Actuals for 2012-2014 included an aggregate $59 million for one-half of the costs of certain smart electric grid projects for which the company received grants from the U. S.  Department of Energy for the other half of the projects’ costs under the American Recovery and Reinvestment Act of 2009.
(b) CECONY’s capital expenditures for environmental protection facilities and related studies were $218 million $178 million and $194 million in 2014, 2013 and 2012, respectively, and are estimated to be $217 million in 2015.
(c) Estimates do not include amounts for transmission projects discussed under “Con Edison Transmission,” above or for the energy efficiency, demand reduction and combined heat and power programs discussed under “CECONY – Electric Operations – Electric Supply,” above.
(d) For 2012, includes $239 million for the May 2012 redemption of all of its preferred stock and $224.6 million of tax-exempt debt which was subject to mandatory tender by bondholders in November 2012.
The Utilities have an ongoing need to make substantial capital investments primarily to maintain the reliability of their electric, gas and steam delivery systems, including programs to strengthen the storm resiliency of their infrastructure and to address the growth in demand for electricity and gas.
Estimated capital expenditures for the competitive energy businesses reflect potential investments in renewable generation and energy infrastructure projects and could significantly increase or decrease from the amounts estimated depending on market conditions and opportunities.
Four of the group’s aircraft – the Gulfstream G350, G450, G500 and G550 – as well as the out-of-production GV, share the same pilot-type rating.
This results in significant savings for multiple-aircraft fleet operators in training and maintenance costs, as well as enhanced safety in the operation of the aircraft.
In 2006, the Aerospace group continued to distinguish its products and services from its competition.
The company brought into service its newest business-jet aircraft, the mid-size, high-speed G150, replacing the G100.
The G150 offers an entirely new cabin design – a wider fuselage and space for larger seats – that can accommodate up to eight passengers.
In March, General Dynamics announced the Aerospace group’s most comprehensive infrastructure renewal program since Gulfstream’s inception in 1958.
This seven-year effort includes a new service center more than twice as large as the current facility; a unique sales and design center to help guide customers through the aircraft purchase and interior-design selection process; expansion of the existing manufacturing facilities; a new engineering building; and new paint hangars.
To ensure its continued leadership in the business-aviation industry, the Aerospace group is committed to ongoing investment in research and development (R&D).
Investments in innovative designs occur across a range of capabilities in aerodynamics; cockpit design and layout; and fuel, electrical and weight efficiencies.
These continue to enhance Gulfstream’s reputation and lead to ongoing new-product offerings and broader customer choice.
To support these efforts, in 2006 the Aerospace group opened the new 100,000-square-foot Gulfstream Research and Development Center.
This facility has centralized the group’s R&D efforts in advanced avionics, flight control systems and cabin technologies; enhanced vision systems, including synthetic vision; and new model concepts.
The company is making these investments to enable the Aerospace group to remain a leader in the business-jet aviation industry.
The Aerospace group offers several product enhancements for new aircraft and upgrades for existing planes to ensure new and current customers benefit from the results of these R&D investments.
Among them is the ultra-high-speed broadband multi-link (BBML) system, which is available for Gulfstream’s large-cabin business-jet aircraft.
This sophisticated technology allows customers to access the Internet at connection speeds similar to those typically found in corporate offices while at altitudes up to 51,000 feet.
Gulfstream’s BBML service is up to 10 times faster than other widely used in-flight connections.
Videoconferencing and Voice-over-Internet Protocol (VoIP) communications capabilities are available as well.
Additionally, the company continues to offer its industryleading Enhanced Vision System (EVS), a specially designed, forward-looking infrared (FLIR) camera that projects an infrared real-world image on the pilot’s heads-up display (HUD).
EVS enables the flight crew to see runway markings, taxiways, adjacent roads and surrounding areas in conditions of low light and reduced visibility, significantly enhancing the safety features of the aircraft.
Customer service remains a key market discriminator for the Aerospace group.
In addition to the new service center planned for the group’s headquarters in Savannah, Georgia, the Aerospace group has expanded service support and pre-positioned spare-parts depots in Asia, Europe, the Middle East and Latin America.
In January 2007, the group announced the acquisition of WECO Aerospace Systems, a privately held aviation-component overhaul company, to augment the group’s service capabilities.
The group’s commitment to product service and support, which has garnered top industry awards for exemplary product support for the past seven years, continues to extend its outstanding record of aircraft safety, reliability and availability.
The company remains a leading provider of aircraft for government special-mission applications, including executive transportation, aerial reconnaissance, maritime surveillance, weather research and astronaut training.
Gulfstream aircraft are ideal for meeting these various mission requirements because of the aircraft’s high-altitude capability, range, endurance, reliability and efficiency.
For example, in 2006 the company delivered a Conformal Airborne Early Warning (CAEW) special-mission aircraft to the Israeli Ministry of Defense.
This program entailed the most extensive exterior modification on a Gulfstream aircraft to date – including additional structural attachments and an enhanced electrical power system.
More than 160 government and special-mission Gulfstream aircraft are in service, completed or on order for 34 nations.
Net sales for the Aerospace group were 17 percent of the company’s consolidated net sales in 2006 and 16 percent in 2005 and 2004.
Net sales by major products and services were as follows:
## Table 2 ##
Loan commitments (unfunded loans and unused lines of credit), asset purchase agreements, standby letters of credit and letters of credit are issued to accommodate the financing needs of State Street’s clients and to provide credit enhancements to special purpose entities.
Loan commitments are agreements by State Street to lend monies at a future date.
Asset purchase agreements are commitments to purchase receivables or securities, subject to conditions established in the agreements, and at December 31, 2001, include $8.0 billion outstanding to special purpose entities.
Standby letters of credit and letters of credit commit State Street to make payments on behalf of clients and special purpose entities when certain specified events occur.
Standby letters of credit outstanding to special purpose entities were $608million at December 31, 2001.
These loan, asset purchase and letter of credit commitments are subject to the same credit policies and reviews as loans.
The amount and nature of collateral are obtained based upon management’s assessment of the credit risk.
Approximately 89% of the loan commitments and asset purchase agreements expire within one year from the date of issue.
Since many of the commitments are expected to expire or renew without being drawn, the total commitment amounts do not necessarily represent future cash requirements.
The following is a summary of the contractual amount of credit-related, off-balance sheet financial instruments at December 31:
## Table 3 ##

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td colspan="2"> March 31, 2011</td></tr><tr><td></td><td>Number of Shares (in thousands)</td><td> Grant Date Fair Value (per share)</td></tr><tr><td>Restricted stock awards at beginning of year</td><td>379</td><td>$15.93</td></tr><tr><td>Granted</td><td>356</td><td>10.00</td></tr><tr><td>Vested</td><td>-79</td><td>12.05</td></tr><tr><td>Forfeited</td><td>-249</td><td>18.63</td></tr><tr><td>Restricted stock awards at end of year</td><td>407</td><td>$9.84</td></tr></table>
<table><tr><td></td><td colspan="3"> Actual</td><td colspan="3"> Estimate</td></tr><tr><td> (Millions of Dollars)</td><td> 2012</td><td> 2013</td><td> 2014</td><td> 2015</td><td> 2016</td><td> 2017</td></tr><tr><td>Regulated utility construction expenditures(a)</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>CECONY(b)(c)</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Electric</td><td>$1,375</td><td>$1,471</td><td>$1,500</td><td>$1,598</td><td>$1,868</td><td>$1,827</td></tr><tr><td>Gas</td><td>426</td><td>536</td><td>549</td><td>679</td><td>687</td><td>808</td></tr><tr><td>Steam</td><td>108</td><td>128</td><td>83</td><td>98</td><td>106</td><td>59</td></tr><tr><td>Sub-total</td><td>1,909</td><td>2,135</td><td>2,132</td><td>2,375</td><td>2,661</td><td>2,694</td></tr><tr><td>O&R</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Electric</td><td>98</td><td>98</td><td>105</td><td>125</td><td>137</td><td>132</td></tr><tr><td>Gas</td><td>39</td><td>37</td><td>37</td><td>37</td><td>45</td><td>45</td></tr><tr><td>Sub-total</td><td>137</td><td>135</td><td>142</td><td>162</td><td>182</td><td>177</td></tr><tr><td>Total regulated utility construction expenditures</td><td>2,046</td><td>2,270</td><td>2,274</td><td>2,537</td><td>2,843</td><td>2,871</td></tr><tr><td>Competitive energy businesses capital expenditures</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Renewable and energy infrastructure projects</td><td>489</td><td>375</td><td>443</td><td>370</td><td>361</td><td>369</td></tr><tr><td>Other</td><td>3</td><td>3</td><td>4</td><td>5</td><td>5</td><td>5</td></tr><tr><td>Sub-total</td><td>492</td><td>378</td><td>447</td><td>375</td><td>366</td><td>374</td></tr><tr><td>Total capital expenditures</td><td>2,538</td><td>2,648</td><td>2,721</td><td>2,912</td><td>3,209</td><td>3,245</td></tr><tr><td>Retirement of long-term securities</td><td></td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Con Edison – parent company</td><td>1</td><td>2</td><td>2</td><td>2</td><td>2</td><td>2</td></tr><tr><td>CECONY(d)</td><td>764</td><td>700</td><td>475</td><td>350</td><td>650</td><td>-</td></tr><tr><td>O&R</td><td>3</td><td>3</td><td>3</td><td>143</td><td>79</td><td>4</td></tr><tr><td>Competitive energy businesses</td><td>1</td><td>1</td><td>5</td><td>65</td><td>-</td><td>-</td></tr><tr><td>Total retirement of long-term securities</td><td>769</td><td>706</td><td>485</td><td>560</td><td>731</td><td>6</td></tr><tr><td>Total capital requirements</td><td>$3,307</td><td>$3,354</td><td>$3,206</td><td>$3,472</td><td>$3,940</td><td>$3,251</td></tr></table>
<table><tr><td> Year Ended December 31</td><td> 2006</td><td> 2005</td><td> 2004</td></tr><tr><td>New aircraft</td><td>$3,341</td><td>$2,730</td><td>$2,288</td></tr><tr><td>Aircraft services</td><td>558</td><td>484</td><td>446</td></tr><tr><td>Pre-owned aircraft</td><td>217</td><td>219</td><td>278</td></tr><tr><td></td><td>$4,116</td><td>$3,433</td><td>$3,012</td></tr></table>
<table><tr><td>(Dollars in millions)</td><td>2001</td><td>2000</td></tr><tr><td>Indemnified securities on loan</td><td>$113,047</td><td>$101,438</td></tr><tr><td>Loan commitments</td><td>12,962</td><td>11,367</td></tr><tr><td>Asset purchase agreements</td><td>10,366</td><td>7,112</td></tr><tr><td>Standby letters of credit</td><td>3,918</td><td>4,028</td></tr><tr><td>Letters of credit</td><td>164</td><td>218</td></tr></table>

Question: How many years does Gas stay higher than Steam?
Answer: 5