Obligations Associated with the Separation of United States Steel On December 31, 2001, we disposed of our steel business through a tax-free distribution of the common stock of our wholly owned subsidiary, United States Steel, to holders of its USX – U.  S.  Steel Group class of common stock (‘‘Steel Stock’’) in exchange for all outstanding shares of Steel Stock on a one-for-one basis (the ‘‘Separation’’).
We remain obligated (primarily or contingently) for certain debt and other financial arrangements for which United States Steel has assumed responsibility for repayment under the terms of the Separation.
United States Steel’s obligations to Marathon are general unsecured obligations that rank equal to United States Steel’s accounts payable and other general unsecured obligations.
If United States Steel fails to satisfy these obligations, we would become responsible for repayment.
Under the Financial Matters Agreement, United States Steel has all of the existing contractual rights under the leases assumed from Marathon, including all rights related to purchase options, prepayments or the grant or release of security interests.
However, United States Steel has no right to increase amounts due under or lengthen the term of any of the assumed leases, other than extensions set forth in the terms of the assumed leases.
As of December 31, 2004, we have identified the following obligations totaling $671 million that have been assumed by United States Steel: ?
$472 million of industrial revenue bonds related to environmental improvement projects for current and former United States Steel facilities, with maturities ranging from 2009 through 2033.
Accrued interest payable on these bonds was $8 million at December 31, 2004.  ?
$71 million of sale-leaseback financing under a lease for equipment at United States Steel’s Fairfield Works, with a term extending to 2012, subject to extensions.
There was no accrued interest payable on this financing at December 31, 2004.  ?
$51 million of obligations under a lease for equipment at United States Steel’s Clairton cokemaking facility, with a term extending to 2012.
There was no accrued interest payable on this financing at December 31, 2004.  ?
$55 million of operating lease obligations, of which $42 million was in turn assumed by purchasers of major equipment used in plants and operations divested by United States Steel.  ?
A guarantee of United States Steel’s $14 million contingent obligation to repay certain distributions from its 50 percent owned joint venture PRO-TEC Coating Company.  ?
A guarantee of all obligations of United States Steel as general partner of Clairton 1314B Partnership, L. P.  to the limited partners.
United States Steel has reported that it currently has no unpaid outstanding obligations to the limited partners.
For further discussion of the Clairton 1314B guarantee, see Note 3 to the Consolidated Financial Statements.
Of the total $671 million, obligations of $602 million and corresponding receivables from United States Steel were recorded on our consolidated balance sheet (current portion – $15 million; long-term portion – $587 million).
The remaining $69 million was related to off-balance sheet arrangements and contingent liabilities of United States Steel.
The table below provides aggregated information on the portion of our obligations to make future payments under existing contracts that have been assumed by United States Steel as of December 31, 2004: Summary of Contractual Cash Obligations Assumed by United States Steel
## Table 0 ##
(a) We anticipate cash payments for interest of $27 million for 2005, $53 million for 2006-2007, $53 million for 2008-2009 and $53 million for the later years to be assumed by United States Steel.
Each of Marathon and United States Steel, as members of the same consolidated tax reporting group during taxable periods ended on or before December 31, 2001, is jointly and severally liable for the federal income tax liability of the entire consolidated tax reporting group for those periods.
Marathon and United States Steel have entered into a tax sharing agreement that allocates tax liabilities relating to taxable periods ended on or before December 31, 2001.
Stock-based awards under the Plan Stock options – Marathon grants stock options under the 2007 Plan and previously granted options under the 2003 Plan.
Marathon’s stock options represent the right to purchase shares of common stock at the fair market value of the common stock on the date of grant.
Through 2004, certain stock options were granted under the 2003 Plan with a tandem stock appreciation right, which allows the recipient to instead elect to receive cash and/or common stock equal to the excess of the fair market value of shares of common stock, as determined in accordance with the 2003 Plan, over the option price of the shares.
In general, stock options granted under the 2007 Plan and the 2003 Plan vest ratably over a three-year period and have a maximum term of ten years from the date they are granted.
Stock appreciation rights – Prior to 2005, Marathon granted SARs under the 2003 Plan.
No stock appreciation rights have been granted under the 2007 Plan.
Similar to stock options, stock appreciation rights represent the right to receive a payment equal to the excess of the fair market value of shares of common stock on the date the right is exercised over the grant price.
Under the 2003 Plan, certain SARs were granted as stock-settled SARs and others were granted in tandem with stock options.
In general, SARs granted under the 2003 Plan vest ratably over a three-year period and have a maximum term of ten years from the date they are granted.
Stock-based performance awards – Prior to 2005, Marathon granted stock-based performance awards under the 2003 Plan.
No stock-based performance awards have been granted under the 2007 Plan.
Beginning in 2005, Marathon discontinued granting stock-based performance awards and instead now grants cash-settled performance units to officers.
All stock-based performance awards granted under the 2003 Plan have either vested or been forfeited.
As a result, there are no outstanding stock-based performance awards.
Restricted stock – Marathon grants restricted stock and restricted stock units under the 2007 Plan and previously granted such awards under the 2003 Plan.
In 2005, the Compensation Committee began granting time-based restricted stock to certain U. S. -based officers of Marathon and its consolidated subsidiaries as part of their annual long-term incentive package.
The restricted stock awards to officers vest three years from the date of grant, contingent on the recipient’s continued employment.
Marathon also grants restricted stock to certain non-officer employees and restricted stock units to certain international employees (“restricted stock awards”), based on their performance within certain guidelines and for retention purposes.
The restricted stock awards to non-officers generally vest in one-third increments over a three-year period, contingent on the recipient’s continued employment.
Prior to vesting, all restricted stock recipients have the right to vote such stock and receive dividends thereon.
The non-vested shares are not transferable and are held by Marathon’s transfer agent.
Common stock units – Marathon maintains an equity compensation program for its non-employee directors under the 2007 Plan and previously maintained such a program under the 2003 Plan.
All non-employee directors other than the Chairman receive annual grants of common stock units, and they are required to hold those units until they leave the Board of Directors.
When dividends are paid on Marathon common stock, directors receive dividend equivalents in the form of additional common stock units.
Stock-based compensation expense – Total employee stock-based compensation expense was $80 million, $83 million and $111 million in 2007, 2006 and 2005.
The total related income tax benefits were $29 million, $31 million and $39 million.
In 2007 and 2006, cash received upon exercise of stock option awards was $27 million and $50 million.
Tax benefits realized for deductions during 2007 and 2006 that were in excess of the stock-based compensation expense recorded for options exercised and other stock-based awards vested during the period totaled $30 million and $36 million.
Cash settlements of stock option awards totaled $1 million and $3 million in 2007 and 2006.
Stock option awards granted – During 2007, 2006 and 2005, Marathon granted stock option awards to both officer and non-officer employees.
The weighted average grant date fair value of these awards was based on the following Black-Scholes assumptions:
## Table 1 ##
The following is a summary of stock-based performance award and restricted stock award activity.
## Table 2 ##
(a) Additional shares were issued in 2006 and 2007 because the performance targets were exceeded for the 36-month performance periods related to the 2003 and 2004 grants.
During 2007, 2006 and 2005 the weighted average grant date fair value of restricted stock awards was $54.97, $40.45 and $27.21.
The vesting date fair value of stock-based performance awards which vested during 2007, 2006 and 2005 was $38 million, $21 million and $5 million.
The vesting date fair value of restricted stock awards which vested during 2007, 2006 and 2005 was $29 million, $32 million and $13 million.
As of December 31, 2007, there was $37 million of unrecognized compensation cost related to restricted stock awards which is expected to be recognized over a weighted average period of 1.4 year.25.
Stockholders’ Equity Common stock – On April 25, 2007, Marathon’s stockholders approved an increase in the number of authorized shares of common stock from 550 million to 1.1 billion shares, and the Company’s Board of Directors subsequently declared a two-for-one split of the Company’s common stock.
The stock split was effected in the form of a stock dividend distributed on June 18, 2007, to stockholders of record at the close of business on May 23, 2007.
Stockholders received one additional share of Marathon Oil Corporation common stock for each share of common stock held as of the close of business on the record date.
In addition, shares of common stock issued or issuable for stock-based awards under Marathon’s incentive compensation plans were proportionately increased in accordance with the terms of the plans.
Common stock and per share (except par value) information for all periods presented has been restated in the consolidated financial statements and notes to reflect the stock split.
During 2007, 2006 and 2005, Marathon had the following common stock issuances in addition to shares issued for employee stock-based awards: ?
On October 18, 2007, in connection with the acquisition of Western discussed in Note 6, Marathon distributed 29 million shares of its common stock valued at $55.70 per share to Western’s shareholders.  ?
On June 30, 2005, in connection with the acquisition of Ashland’s minority interest in MPC discussed in Note 6, Marathon distributed 35 million shares of its common stock valued at $27.23 per share to Ashland’s shareholders.
Marathon’s Board of Directors has authorized the repurchase of up to $5 billion of common stock.
Purchases under the program may be in either open market transactions, including block purchases, or in privately negotiated transactions.
The Company will use cash on hand, cash generated from operations, proceeds from potential asset sales or cash from available borrowings to acquire shares.
This program may be changed based upon the Company’s financial condition or changes in market conditions and is subject to termination prior to completion.
The repurchase program does not include specific price targets or timetables.
As of December 31, 2007, the Company had acquired 58 million common shares at a cost of $2.520 billion under the program, including 16 million common shares acquired during 2007 at a cost of $822 million and 42 million common shares acquired during 2006 at a cost of $1.698 billion.

<table><tr><td><i>(Dollars in millions)</i>  </td><td> Total </td><td> 2005 </td><td> 2006- 2007 </td><td> 2008- 2009 </td><td> Later Years </td></tr><tr><td> Contractual obligations assumed by United States Steel</td><td></td><td></td><td></td><td></td><td></td></tr><tr><td>Long-term debt<sup>(a)</sup></td><td>$472</td><td>$–</td><td>$–</td><td>$–</td><td>$472</td></tr><tr><td>Sale-leaseback financing (includes imputed interest)</td><td>96</td><td>11</td><td>30</td><td>22</td><td>33</td></tr><tr><td>Capital lease obligations</td><td>71</td><td>4</td><td>19</td><td>19</td><td>29</td></tr><tr><td>Operating lease obligations</td><td>13</td><td>5</td><td>8</td><td>–</td><td>–</td></tr><tr><td>Operating lease obligations under sublease</td><td>42</td><td>5</td><td>10</td><td>11</td><td>16</td></tr><tr><td> Total contractual obligations assumed by United States Steel</td><td>$694</td><td>$25</td><td>$67</td><td>$52</td><td>$550</td></tr></table>
<table><tr><td></td><td>2007</td><td>2006</td><td>2005</td></tr><tr><td>Weighted average exercise price per share</td><td>$60.94</td><td>$37.84</td><td>$25.14</td></tr><tr><td>Expected annual dividends per share</td><td>$0.96</td><td>$0.80</td><td>$0.66</td></tr><tr><td>Expected life in years</td><td>5.0</td><td>5.1</td><td>5.5</td></tr><tr><td>Expected volatility</td><td>27%</td><td>28%</td><td>28%</td></tr><tr><td>Risk-free interest rate</td><td>4.1%</td><td>5.0%</td><td>3.8%</td></tr><tr><td>Weighted average grant date fair value of stock option awards granted</td><td>$17.24</td><td>$10.19</td><td>$6.15</td></tr></table>
<table><tr><td></td><td>Stock-Based Performance Awards</td><td>WeightedAverage GrantDate Fair Value</td><td>Restricted Stock Awards</td><td>WeightedAverage GrantDate Fair Value</td></tr><tr><td>Unvested at December 31, 2005</td><td>897,200</td><td>$14.97</td><td>1,971,112</td><td>$23.97</td></tr><tr><td>Granted</td><td>135,696(a)</td><td>38.41</td><td>437,960</td><td>40.45</td></tr><tr><td>Vested</td><td>-546,896</td><td>19.15</td><td>-777,194</td><td>20.59</td></tr><tr><td>Forfeited</td><td>-12,000</td><td>16.81</td><td>-79,580</td><td>26.55</td></tr><tr><td>Unvested at December 31, 2006</td><td>474,000</td><td>16.81</td><td>1,552,298</td><td>30.21</td></tr><tr><td>Granted</td><td>393,420(a)</td><td>44.13</td><td>572,897</td><td>54.97</td></tr><tr><td>Vested</td><td>-867,420</td><td>29.20</td><td>-557,096</td><td>28.86</td></tr><tr><td>Forfeited</td><td>–</td><td>–</td><td>-40,268</td><td>34.55</td></tr><tr><td>Unvested at December 31, 2007</td><td>–</td><td>–</td><td>1,527,831</td><td>39.87</td></tr></table>

Question: by how much did the weighted average exercise price per share increase from 2005 to 2007?
Answer: 1.42403