4 .stock options and other stock plans we have 100962 options outstanding under the 1993 stock option and retention stock plan of union pacific corporation ( 1993 plan ) .there are 7140 restricted shares outstanding under the 1992 restricted stock plan for non-employee directors of union pacific corporation .we no longer grant options or awards of retention shares and units under these plans .in april 2000 , the shareholders approved the union pacific corporation 2000 directors plan ( directors plan ) whereby 1100000 shares of our common stock were reserved for issuance to our non-employee directors .under the directors plan , each non-employee director , upon his or her initial election to the board of directors , receives a grant of 2000 shares of retention shares or retention stock units .prior to december 31 , 2007 , each non-employee director received annually an option to purchase at fair value a number of shares of our common stock , not to exceed 10000 shares during any calendar year , determined by dividing 60000 by 1/3 of the fair market value of one share of our common stock on the date of such board of directors meeting , with the resulting quotient rounded up or down to the nearest 50 shares .as of december 31 , 2009 , 18000 restricted shares were outstanding under the directors plan and 292000 options were outstanding under the directors plan .the union pacific corporation 2001 stock incentive plan ( 2001 plan ) was approved by the shareholders in april 2001 .the 2001 plan reserved 24000000 shares of our common stock for issuance to eligible employees of the corporation and its subsidiaries in the form of non-qualified options , incentive stock options , retention shares , stock units , and incentive bonus awards .non-employee directors were not eligible for awards under the 2001 plan .as of december 31 , 2009 , 3366230 options were outstanding under the 2001 plan .we no longer grant any stock options or other stock or unit awards under this plan .the union pacific corporation 2004 stock incentive plan ( 2004 plan ) was approved by shareholders in april 2004 .the 2004 plan reserved 42000000 shares of our common stock for issuance , plus any shares subject to awards made under the 2001 plan and the 1993 plan that were outstanding on april 16 , 2004 , and became available for regrant pursuant to the terms of the 2004 plan .under the 2004 plan , non- qualified options , stock appreciation rights , retention shares , stock units , and incentive bonus awards may be granted to eligible employees of the corporation and its subsidiaries .non-employee directors are not eligible for awards under the 2004 plan .as of december 31 , 2009 , 8939710 options and 3778997 retention shares and stock units were outstanding under the 2004 plan .pursuant to the above plans 33559150 ; 36961123 ; and 38601728 shares of our common stock were authorized and available for grant at december 31 , 2009 , 2008 , and 2007 , respectively .stock options 2013 we estimate the fair value of our stock option awards using the black-scholes option pricing model .groups of employees and non-employee directors that have similar historical and expected exercise behavior are considered separately for valuation purposes .the table below shows the annual weighted-average assumptions used for valuation purposes : weighted-average assumptions 2009 2008 2007 .
[['weighted-average assumptions', '2009', '2008', '2007'], ['risk-free interest rate', '1.9% ( 1.9 % )', '2.8% ( 2.8 % )', '4.9% ( 4.9 % )'], ['dividend yield', '2.3% ( 2.3 % )', '1.4% ( 1.4 % )', '1.4% ( 1.4 % )'], ['expected life ( years )', '5.1', '5.3', '4.7'], ['volatility', '31.3% ( 31.3 % )', '22.2% ( 22.2 % )', '20.9% ( 20.9 % )'], ['weighted-average grant-date fair value of options granted', '$ 11.33', '$ 13.35', '$ 11.19']]
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Question: how many options were issued under the 2001 plan as of december 31 , 2009?
Answer: 20633770