pre_text: the following table illustrates the pro forma effect on net income and earnings per share as if all outstanding and unvested stock options in 2005 were accounted for using estimated fair value . 2005year ended december 31 .
post_text: basic earnings per share is calculated by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period , which excludes unvested shares of restricted stock . diluted earnings per share is calculated by dividing net income available to common shareholders by the weighted-average number of common shares outstanding for the period and the shares representing the dilutive effect of stock options and awards and other equity-related financial instruments . the effect of stock options and restricted stock outstanding is excluded from the calculation of diluted earnings per share in periods in which their effect would be antidilutive . special purpose entities : we are involved with various legal forms of special purpose entities , or spes , in the normal course of our business . we use trusts to structure and sell certificated interests in pools of tax-exempt investment-grade assets principally to our mutual fund customers . these trusts are recorded in our consolidated financial statements . we transfer assets to these trusts , which are legally isolated from us , from our investment securities portfolio at adjusted book value . the trusts finance the acquisition of these assets by selling certificated interests issued by the trusts to third-party investors . the investment securities of the trusts are carried in investments securities available for sale at fair value . the certificated interests are carried in other short-term borrowings at the amount owed to the third-party investors . the interest revenue and interest expense generated by the investments and certificated interests , respectively , are recorded in net interest revenue when earned or incurred. .
table: Year ended December 31, 2005
table: (In millions, except per share amounts)
table: Net income as reported $838
table: Add: Stock option compensation expense included in reported net income, net of related taxes 20
table: Deduct: Total stock option compensation expense determined under fair value method for all awards, net of related taxes (27)
table: Pro forma net income $831
table: Earnings per share:
table: Basic—as reported $2.53
table: Basic—pro forma 2.51
table: Diluted—as reported 2.50
table: Diluted—pro forma 2.48
question: Analyse this data from a financial earnings document. what is the number of outstanding shares based on the eps , ( in millions ) ?