five-year performance comparison 2013 the following graph provides an indicator of cumulative total shareholder returns for the corporation as compared to the peer group index ( described above ) , the dj trans , and the s&p 500 . the graph assumes that $ 100 was invested in the common stock of union pacific corporation and each index on december 31 , 2007 and that all dividends were reinvested . purchases of equity securities 2013 during 2012 , we repurchased 13804709 shares of our common stock at an average price of $ 115.33 . the following table presents common stock repurchases during each month for the fourth quarter of 2012 : period total number of shares purchased [a] average price paid per share total number of shares purchased as part of a publicly announced plan or program [b] maximum number of shares that may yet be purchased under the plan or program [b] .
[a] total number of shares purchased during the quarter includes approximately 105978 shares delivered or attested to upc by employees to pay stock option exercise prices , satisfy excess tax withholding obligations for stock option exercises or vesting of retention units , and pay withholding obligations for vesting of retention shares . [b] on april 1 , 2011 , our board of directors authorized the repurchase of up to 40 million shares of our common stock by march 31 , 2014 . these repurchases may be made on the open market or through other transactions . our management has sole discretion with respect to determining the timing and amount of these transactions. .
<i>Period</i> <i>Total Number ofSharesPurchased [a]</i> <i>AveragePrice PaidPer Share</i> <i>Total Number of Shares</i><i>Purchased as Part of a</i><i>Publicly Announced Plan</i><i>or Program [b]</i> <i>Maximum Number of</i><i>Shares That May Yet</i><i>Be Purchased Under the Plan</i><i>or Program [b]</i>
Oct. 1 through Oct. 31 1,068,414 121.70 1,028,300 16,041,399
Nov. 1 through Nov. 30 659,631 120.84 655,000 15,386,399
Dec. 1 through Dec. 31 411,683 124.58 350,450 15,035,949
Total 2,139,728 $121.99 2,033,750 N/A
period total number ofsharespurchased [a] averageprice paidper share total number of sharespurchased as part of apublicly announced planor program [b] maximum number ofshares that may yetbe purchased under the planor program [b]
oct . 1 through oct . 31 1068414 121.70 1028300 16041399
nov . 1 through nov . 30 659631 120.84 655000 15386399
dec . 1 through dec . 31 411683 124.58 350450 15035949
total 2139728 $ 121.99 2033750 n/a
what portion of the 2011 plan repurchases were repurchased in 2012?