abiomed , inc . and subsidiaries notes to consolidated financial statements 2014 ( continued ) note 8 . stock award plans and stock-based compensation ( continued ) restricted stock and restricted stock units the following table summarizes restricted stock and restricted stock unit activity for the fiscal year ended march 31 , 2012 : number of shares ( in thousands ) weighted average grant date fair value ( per share ) .
for equity awards where the performance criteria has been met in 2012 , what is the average compensation expense per year over which the cost will be expensed?
the remaining unrecognized compensation expense for outstanding restricted stock and restricted stock units , including performance-based awards , as of march 31 , 2012 was $ 7.1 million and the weighted-average period over which this cost will be recognized is 2.2 years . the weighted average grant-date fair value for restricted stock and restricted stock units granted during the years ended march 31 , 2012 , 2011 , and 2010 was $ 18.13 , $ 10.00 and $ 7.67 per share , respectively . the total fair value of restricted stock and restricted stock units vested in fiscal years 2012 , 2011 , and 2010 was $ 1.5 million , $ 1.0 million and $ 0.4 million , respectively . performance-based awards included in the restricted stock and restricted stock units activity discussed above are certain awards granted in fiscal years 2012 , 2011 and 2010 that vest subject to certain performance-based criteria . in june 2010 , 311000 shares of restricted stock and a performance-based award for the potential issuance of 45000 shares of common stock were issued to certain executive officers and members of senior management of the company , all of which would vest upon achievement of prescribed service milestones by the award recipients and performance milestones by the company . during the year ended march 31 , 2011 , the company determined that it met the prescribed performance targets and a portion of these shares and stock options vested . the remaining shares will vest upon satisfaction of prescribed service conditions by the award recipients . during the three months ended june 30 , 2011 , the company determined that it should have been using the graded vesting method instead of the straight-line method to expense stock-based compensation for the performance-based awards issued in june 2010 . this resulted in additional stock based compensation expense of approximately $ 0.6 million being recorded during the three months ended june 30 , 2011 that should have been recorded during the year ended march 31 , 2011 . the company believes that the amount is not material to its march 31 , 2011 consolidated financial statements and therefore recorded the adjustment in the quarter ended june 30 , 2011 . during the three months ended june 30 , 2011 , performance-based awards of restricted stock units for the potential issuance of 284000 shares of common stock were issued to certain executive officers and members of the senior management , all of which would vest upon achievement of prescribed service milestones by the award recipients and revenue performance milestones by the company . as of march 31 , 2012 , the company determined that it met the prescribed targets for 184000 shares underlying these awards and it believes it is probable that the prescribed performance targets will be met for the remaining 100000 shares , and the compensation expense is being recognized accordingly . during the year ended march 31 , 2012 , the company has recorded $ 3.3 million in stock-based compensation expense for equity awards in which the prescribed performance milestones have been achieved or are probable of being achieved . the remaining unrecognized compensation expense related to these equity awards at march 31 , 2012 is $ 3.6 million based on the company 2019s current assessment of probability of achieving the performance milestones . the weighted-average period over which this cost will be recognized is 2.1 years. .