Table of Contents MARKETAXESS HOLDINGS INC.  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – (Continued) The following is a summary of the Company’s net deferred tax assets:
## Table 0 ##
As of December 31, 2013, the Company had deferred tax assets associated with stock-based compensation of approximately $6.0 million.
There is a risk that the ultimate tax benefit realized upon the exercise of stock options or vesting of restricted stock could be less than the tax benefit previously recognized and exhaust the additional-paid-in-capital pool.
If this should occur, any excess tax benefit previously recognized would be reversed, resulting in an increase in tax expense.
Since the tax benefit to be realized in the future is unknown, it is not currently possible to estimate the impact on the deferred tax balance.
As of December 31, 2013, the additional paid-in-capital pool, which is determined under a one pool approach for employee and non-employee awards, was approximately $48.4 million.
The additional paid-in-capital pool is currently sufficient to absorb a complete write-off of the stock-based compensation deferred tax asset.
In 2001 and 2000, MarketAxess Holdings Inc.  and MarketAxess Corporation had an ownership change within the meaning of Section 382 of the Internal Revenue Code.
As of December 31, 2013, the Company had restricted U. S.  federal net operating loss carryforwards of approximately $9.3 million, which begin to expire in 2021.
The Company’s net operating loss carryforwards may be subject to additional annual limitations if there is a 50% or greater change in the Company’s ownership, as determined over a rolling three-year period.
In addition, the Company has $0.7 million of foreign loss carry forwards which begin to expire in 2025.
The Company issued warrants to certain broker-dealer stockholders at the time that they made an equity investment in the Company.
All of the warrants were exercised prior to 2008.
Through December 31, 2009, the tax benefit on a portion of the tax deduction generated on the exercise of the warrants had not yet been recorded.
During 2010, the Company recognized a portion of the tax benefits amounting to $11.4 million as an increase to additional paid-in-capital due to the utilization of the related tax loss carryforwards of $31.0 million.
During the first quarter of 2011, the Company recognized the remaining portion of the tax benefit, amounting to $4.2 million, as an increase to additional paidin-capital due to the expected utilization of the related tax loss carryforwards of $10.4 million.
The ultimate realization of deferred income tax assets is dependent upon the generation of future taxable income during the periods in which the temporary differences become deductible.
If it is not more likely than not that some portion or all of the gross deferred income tax assets will be realized in future years, a valuation allowance is recorded.
As of December 31, 2013, the valuation allowance relates to certain capital loss, foreign and state tax loss carryforwards that are not expected to be realized.
The Company recognized a $20.6 million capital loss on the sale of Greenline Financial Technologies, Inc.  (“Greenline”) (See Note 14, “Sale of Discontinued Operations”) of which $1.2 million was carried back or otherwise utilized against current period capital gains.
A full valuation allowance was provided against the remaining capital loss carryforward.
Table of Contents MARKETAXESS HOLDINGS INC.  NOTES TO CONSOLIDATED FINANCIAL STATEMENTS – (Continued) Stock Options The exercise price of each option granted is equal to the market price of the Company’s common stock on the date of grant.
Generally, option grants have provided for vesting over a three or five-year period.
Options expire ten years from the date of grant.
The fair value of each option award is estimated on the date of grant using the Black-Scholes option-pricing model.
The determination of fair value of share-based payment awards on the date of grant using an option-pricing model is affected by the Company’s stock price as well as assumptions regarding a number of highly complex and subjective variables, including the expected stock price volatility over the term of the awards, the risk-free interest rate and the expected term.
Expected volatilities are based on historical volatility of the Company’s stock and a peer group.
The risk-free interest rate is based on U. S.  Treasury securities with a maturity value approximating the expected term of the option.
The expected term represents the period of time that options granted are expected to be outstanding based on actual and projected employee stock option exercise behavior.
The weighted-average fair value for options granted during 2013, 2012 and 2011 was $19.61, $12.26 and $11.29, respectively.
The following table represents the assumptions used for the Black-Scholes option-pricing model to determine the per share weighted-average fair value for options granted for the three years ended December 31, 2013:
## Table 1 ##
The following table reports stock option activity during the three years ended December 31, 2013 and the intrinsic value as of December 31, 2013:
## Table 2 ##
The intrinsic value is the amount by which the closing price of the Company’s common stock on December 31, 2013 of $66.93 or the price on the day of exercise exceeds the exercise price of the stock options multiplied by the number of shares.
As of December 31, 2013, there was $1.8 million of total unrecognized compensation cost related to non-vested stock options.
That cost is expected to be recognized over a weighted-average period of 2.5 years.
Item 7.
Management’s Discussion and Analysis of Financial Condition and Results of Operations We are an international energy company with operations in the U. S. , Canada, Africa, the Middle East and Europe.
Our operations are organized into three reportable segments: ?
E&P which explores for, produces and markets liquid hydrocarbons and natural gas on a worldwide basis.  ?
OSM which mines, extracts and transports bitumen from oil sands deposits in Alberta, Canada, and upgrades the bitumen to produce and market synthetic crude oil and vacuum gas oil.  ?
IG which produces and markets products manufactured from natural gas, such as LNG and methanol, in EG.
Certain sections of Management’s Discussion and Analysis of Financial Condition and Results of Operations include forward-looking statements concerning trends or events potentially affecting our business.
These statements typically contain words such as “anticipates,” “believes,” “estimates,” “expects,” “targets,” “plans,” “projects,” “could,” “may,” “should,” “would” or similar words indicating that future outcomes are uncertain.
In accordance with “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995, these statements are accompanied by cautionary language identifying important factors, though not necessarily all such factors, which could cause future outcomes to differ materially from those set forth in forward-looking statements.
For additional risk factors affecting our business, see Item 1A.
Risk Factors in this Annual Report on Form 10-K.  Management’s Discussion and Analysis of Financial Condition and Results of Operations should be read in conjunction with the information under Item 1.  Business, Item 1A.
Risk Factors and Item 8.
Financial Statements and Supplementary Data found in this Annual Report on Form 10-K.  Spin-off Downstream Business On June 30, 2011, the spin-off of Marathon’s downstream business was completed, creating two independent energy companies: Marathon Oil and MPC.
Marathon shareholders at the close of business on the record date of June 27, 2011 received one share of MPC common stock for every two shares of Marathon common stock held.
Fractional shares of MPC common stock were not distributed and any fractional share of MPC common stock otherwise issuable to a Marathon shareholder was sold in the open market on such shareholder’s behalf, and such shareholder received a cash payment with respect to that fractional share.
A private letter tax ruling received in June 2011 from the IRS affirmed the tax-free nature of the spin-off.
Activities related to the downstream business have been treated as discontinued operations in all periods presented in this Annual Report on Form 10-K (see Item 8.
Financial Statements and Supplementary Data—Note 3 to the consolidated financial statements for additional information).
Overview – Market Conditions Exploration and Production Prevailing prices for the various grades of crude oil and natural gas that we produce significantly impact our revenues and cash flows.
Prices of crude oil have been volatile in recent years.
In 2011, crude prices increased over 2010 levels, with increases in Brent averages outstripping those in WTI.
During much of 2010, both WTI and Brent crude oil monthly average prices remained in the $75 to $85 per barrel range.
Crude oil prices reached a low of $33.98 in February 2009, following global demand declines in an economic recession, but recovered quickly ending 2009 at $79.36.
The following table lists benchmark crude oil and natural gas price annual averages for the past three years.
## Table 3 ##
(a) Settlement date average.
Our U. S.  crude oil production was approximately 58 percent sour in 2011 and 68 percent in 2010.
Sour crude contains more sulfur than light sweet WTI does.
Sour crude oil also tends to be heavier than light sweet crude oil and sells at a discount to light sweet crude oil because of higher refining costs and lower refined product values.
Our international crude oil production is relatively sweet and is generally sold in relation to the Brent crude benchmark.
The differential between WTI and Brent average prices widened significantly in 2011 to $16.15 in comparison to differentials of less than $1.00 in 2010 and 2009.

Tables referenced above, in order (Table 0 first):
<table><tr><td></td><td colspan="2">As of December 31,</td></tr><tr><td></td><td>2013</td><td>2012</td></tr><tr><td></td><td colspan="2">(In thousands)</td></tr><tr><td>Deferred tax assets</td><td></td><td></td></tr><tr><td>U.S. net operating loss carryforwards</td><td>$4,273</td><td>$7,175</td></tr><tr><td>Foreign net operating loss carryforwards</td><td>101</td><td>160</td></tr><tr><td>Capital loss carryforwards</td><td>7,487</td><td>—</td></tr><tr><td>Stock compensation expense</td><td>6,022</td><td>5,296</td></tr><tr><td>Other</td><td>3,206</td><td>2,839</td></tr><tr><td>Total deferred tax assets</td><td>21,089</td><td>15,470</td></tr><tr><td>Valuation allowance</td><td>-7,743</td><td>-727</td></tr><tr><td>Net deferred tax assets</td><td>13,346</td><td>14,743</td></tr><tr><td>Deferred tax liabilities</td><td></td><td></td></tr><tr><td>Depreciation and amortization</td><td>-1,905</td><td>-2,025</td></tr><tr><td>Capitalized software development costs</td><td>-4,163</td><td>-2,752</td></tr><tr><td>Intangible assets</td><td>-2,331</td><td>-524</td></tr><tr><td>Deferred tax assets, net</td><td>$4,947</td><td>$9,442</td></tr></table>
<table><tr><td></td><td>2013</td><td>2012</td><td> 2011</td></tr><tr><td>Expected life (years)</td><td>9.9</td><td>5.0</td><td>9.9</td></tr><tr><td>Risk-free interest rate</td><td>1.9%</td><td>0.7%</td><td>3.3%</td></tr><tr><td>Expected volatility</td><td>44.3%</td><td>48.2%</td><td>48.0%</td></tr><tr><td>Expected dividend yield</td><td>1.2%</td><td>1.2%</td><td>1.3%</td></tr></table>
<table><tr><td></td><td></td><td></td><td> Remaining</td><td></td></tr><tr><td></td><td>Number of</td><td> Weighted-Average</td><td> Contractual</td><td></td></tr><tr><td></td><td>Shares</td><td> Exercise Price ($)</td><td> Term</td><td> Intrinsic Value ($)  (In thousands)</td></tr><tr><td>Outstanding at December 31, 2010</td><td>4,403,562</td><td>9.09</td><td></td><td></td></tr><tr><td>Granted</td><td>340,771</td><td>21.60</td><td></td><td></td></tr><tr><td>Canceled</td><td>-211,323</td><td>16.16</td><td></td><td></td></tr><tr><td>Exercised</td><td>-1,605,273</td><td>10.21</td><td></td><td></td></tr><tr><td>Outstanding at December 31, 2011</td><td>2,927,737</td><td>9.42</td><td></td><td></td></tr><tr><td>Granted</td><td>13,292</td><td>32.45</td><td></td><td></td></tr><tr><td>Canceled</td><td>—</td><td>—</td><td></td><td></td></tr><tr><td>Exercised</td><td>-1,511,207</td><td>5.64</td><td></td><td></td></tr><tr><td>Outstanding at December 31, 2012</td><td>1,429,822</td><td>13.62</td><td></td><td></td></tr><tr><td>Granted</td><td>51,597</td><td>41.75</td><td></td><td></td></tr><tr><td>Canceled</td><td>-4,348</td><td>33.84</td><td></td><td></td></tr><tr><td>Exercised</td><td>-256,622</td><td>12.33</td><td></td><td>10,723</td></tr><tr><td>Outstanding at December 31, 2013</td><td>1,220,449</td><td>15.01</td><td>4.0</td><td>63,369</td></tr><tr><td>Exercisable at December 31, 2013</td><td>1,023,337</td><td>12.68</td><td>3.4</td><td>55,515</td></tr></table>
<table><tr><td>Benchmark</td><td>2011</td><td>2010</td><td>2009</td></tr><tr><td>WTI crude oil<i>(Dollars per bbl)</i></td><td>$95.11</td><td>$79.61</td><td>$62.09</td></tr><tr><td>Brent (Europe) crude oil<i>(Dollars per bbl)</i></td><td>111.26</td><td>79.51</td><td>61.49</td></tr><tr><td>Henry Hub natural gas<i>(Dollars per mmbtu)</i><sup>(a)</sup></td><td>$4.04</td><td>$4.39</td><td>$3.99</td></tr></table>

Question: by how much did the brent crude oil benchmark increase from 2010 to 2011?
Answer: 0.39932
Reasoning program: subtract(111.26,79.51), divide(#0,79.51)