morgan stanley notes to consolidated financial statements 2014 ( continued ) 16 .
shareholders 2019 equity .
common stock .
changes in shares of common stock outstanding for fiscal 2007 and fiscal 2006 were as follows ( share data in millions ) : fiscal fiscal .

Fiscal 2007
Fiscal 2006
Shares outstanding at beginning of period
1,049
1,058
Net impact of stock option exercises and other share issuances
59
43
Treasury stock purchases
(52)
(52)
Shares outstanding at end of period
1,056
1,049

treasury shares .
during fiscal 2007 , the company purchased $ 3.8 billion of its common stock through open market purchases at an average cost of $ 72.65 per share .
during fiscal 2006 , the company purchased $ 3.4 billion of its common stock through open market purchases at an average cost of $ 65.43 per share .
in december 2006 , the company announced that its board of directors had authorized the repurchase of up to $ 6 billion of the company 2019s outstanding common stock .
this share repurchase authorization considers , among other things , business segment capital needs , as well as equity-based compensation and benefit plan requirements .
as of november 30 , 2007 , the company had approximately $ 2.3 billion remaining under its current share repurchase authorization .
rabbi trusts .
the company has established rabbi trusts ( the 201crabbi trusts 201d ) to provide common stock voting rights to certain employees who hold outstanding restricted stock units .
the number of shares of common stock outstanding in the rabbi trusts was approximately 107 million at november 30 , 2007 and approximately 81 million at november 30 , 2006 .
the assets of the rabbi trusts are consolidated with those of the company , and the value of the company 2019s stock held in the rabbi trusts is classified in shareholders 2019 equity and generally accounted for in a manner similar to treasury stock .
preferred stock .
in july 2006 , the company issued 44000000 depositary shares , in an aggregate of $ 1100 million .
each depositary share represents 1/1000th of a share of floating rate non-cumulative preferred stock , series a , $ 0.01 par value ( 201cseries a preferred stock 201d ) .
the series a preferred stock is redeemable at the company 2019s option , in whole or in part , on or after july 15 , 2011 at a redemption price of $ 25000 per share ( equivalent to $ 25 per depositary share ) .
the series a preferred stock also has a preference over the company 2019s common stock upon liquidation .
subsequent to fiscal year-end , the company declared a quarterly dividend of $ 379.66 per share of series a preferred stock that was paid on january 15 , 2008 to preferred shareholders of record on december 31 , 2007 .
regulatory requirements .
on april 1 , 2007 , the company merged msdwi into ms&co .
upon completion of the merger , the surviving entity , ms&co. , became the company 2019s principal u.s .
broker-dealer .
ms&co .
is a registered broker-dealer and registered futures commission merchant and , accordingly , is subject to the minimum net capital requirements of the securities and exchange commission ( the 201csec 201d ) , the financial industry regulatory authority and the commodity futures trading commission .
ms&co .
has consistently operated in excess of these requirements .
ms&co . 2019s net capital totaled $ 6673 million at november 30 , 2007 , which exceeded the amount required by $ 4950 million .
msip , a london-based broker-dealer subsidiary , is subject to the capital requirements of the financial services authority , and msjs , a tokyo-based broker-dealer subsidiary , is subject to the capital requirements of the financial services agency .
msip and msjs consistently operated in excess of their respective regulatory capital requirements. .

Question: Analyse this data from a financial earnings document. what was the net change in common stock outstanding in millions between 2006 and 2007?
Choices:
7.0
-7
855
0
2105
Correct choice index: 0