stock-based compensation 2013 we have several stock-based compensation plans under which employees and non-employee directors receive stock options , nonvested retention shares , and nonvested stock units .we refer to the nonvested shares and stock units collectively as 201cretention awards 201d .we issue treasury shares to cover option exercises and stock unit vestings , while new shares are issued when retention shares vest .we adopted fasb statement no .123 ( r ) , share-based payment ( fas 123 ( r ) ) , on january 1 , 2006 .fas 123 ( r ) requires us to measure and recognize compensation expense for all stock-based awards made to employees and directors , including stock options .compensation expense is based on the calculated fair value of the awards as measured at the grant date and is expensed ratably over the service period of the awards ( generally the vesting period ) .the fair value of retention awards is the stock price on the date of grant , while the fair value of stock options is determined by using the black-scholes option pricing model .we elected to use the modified prospective transition method as permitted by fas 123 ( r ) and did not restate financial results for prior periods .we did not make an adjustment for the cumulative effect of these estimated forfeitures , as the impact was not material .as a result of the adoption of fas 123 ( r ) , we recognized expense for stock options in 2006 , in addition to retention awards , which were expensed prior to 2006 .stock-based compensation expense for the year ended december 31 , 2006 was $ 22 million , after tax , or $ 0.08 per basic and diluted share .this includes $ 9 million for stock options and $ 13 million for retention awards for 2006 .before taxes , stock-based compensation expense included $ 14 million for stock options and $ 21 million for retention awards for 2006 .we recorded $ 29 million of excess tax benefits as an inflow of financing activities in the consolidated statement of cash flows for the year ended december 31 , 2006 .prior to the adoption of fas 123 ( r ) , we applied the recognition and measurement principles of accounting principles board opinion no .25 , accounting for stock issued to employees , and related interpretations .no stock- based employee compensation expense related to stock option grants was reflected in net income , as all options granted under those plans had a grant price equal to the market value of our common stock on the date of grant .stock-based compensation expense related to retention shares , stock units , and other incentive plans was reflected in net income .the following table details the effect on net income and earnings per share had compensation expense for all of our stock-based awards , including stock options , been recorded in the years ended december 31 , 2005 and 2004 based on the fair value method under fasb statement no .123 , accounting for stock-based compensation .pro forma stock-based compensation expense year ended december 31 , millions of dollars , except per share amounts 2005 2004 .
[['pro forma stock-based compensation expense', 'pro forma stock-based compensation expense', ''], ['millions of dollars except per share amounts', '2005', '2004'], ['net income as reported', '$ 1026', '$ 604'], ['stock-based employee compensation expense reported in net income net of tax', '13', '13'], ['total stock-based employee compensation expense determined under fair value 2013based method for allawards net of tax [a]', '-50 ( 50 )', '-35 ( 35 )'], ['pro forma net income', '$ 989', '$ 582'], ['earnings per share 2013 basic as reported', '$ 3.89', '$ 2.33'], ['earnings per share 2013 basic pro forma', '$ 3.75', '$ 2.25'], ['earnings per share 2013 diluted as reported', '$ 3.85', '$ 2.30'], ['earnings per share 2013 diluted pro forma', '$ 3.71', '$ 2.22']]
[a] stock options for executives granted in 2003 and 2002 included a reload feature .this reload feature allowed executives to exercise their options using shares of union pacific corporation common stock that they already owned and obtain a new grant of options in the amount of the shares used for exercise plus any shares withheld for tax purposes .the reload feature of these option grants could only be exercised if the .

Question: what was the percentage of the increase in the basic earnings per share 2013 as reported from 2005 to 2006
Answer: 66.9%