during the year ended december 31 , 2011 , we granted 354660 performance share units having a fair value based on our grant date closing stock price of $ 28.79 . these units are payable in stock and are subject to certain financial performance criteria . the fair value of these performance share unit awards is based on the grant date closing stock price of each respective award grant and will apply to the number of units ultimately awarded . the number of shares ultimately issued for each award will be based on our financial performance as compared to peer group companies over the performance period and can range from zero to 200% ( 200 % ) . as of december 31 , 2011 , estimated share payouts for outstanding non-vested performance share unit awards ranged from 150% ( 150 % ) to 195% ( 195 % ) . for the legacy frontier performance share units assumed at july 1 , 2011 , performance is based on market performance criteria , which is calculated as the total shareholder return achieved by hollyfrontier stockholders compared with the average shareholder return achieved by an equally-weighted peer group of independent refining companies over a three-year period . these share unit awards are payable in stock based on share price performance relative to the defined peer group and can range from zero to 125% ( 125 % ) of the initial target award . these performance share units were valued at july 1 , 2011 using a monte carlo valuation model , which simulates future stock price movements using key inputs including grant date and measurement date stock prices , expected stock price performance , expected rate of return and volatility of our stock price relative to the peer group over the three-year performance period . the fair value of these performance share units at july 1 , 2011 was $ 8.6 million . of this amount , $ 7.3 million relates to post-merger services and will be recognized ratably over the remaining service period through 2013 . a summary of performance share unit activity and changes during the year ended december 31 , 2011 is presented below: .
in 2011 what was the percent of the change in the performance shares outstanding
( 1 ) includes 225116 non-vested performance share grants under the legacy frontier plan that were outstanding and retained by hollyfrontier at july 1 , 2011 . for the year ended december 31 , 2011 we issued 178148 shares of our common stock having a fair value of $ 2.6 million related to vested performance share units . based on the weighted average grant date fair value of $ 20.71 there was $ 11.7 million of total unrecognized compensation cost related to non-vested performance share units . that cost is expected to be recognized over a weighted-average period of 1.1 years . note 7 : cash and cash equivalents and investments in marketable securities our investment portfolio at december 31 , 2011 consisted of cash , cash equivalents and investments in debt securities primarily issued by government and municipal entities . we also hold 1000000 shares of connacher oil and gas limited common stock that was received as partial consideration upon the sale of our montana refinery in we invest in highly-rated marketable debt securities , primarily issued by government and municipal entities that have maturities at the date of purchase of greater than three months . we also invest in other marketable debt securities with the maximum maturity or put date of any individual issue generally not greater than two years from the date of purchase . all of these instruments , including investments in equity securities , are classified as available- for-sale . as a result , they are reported at fair value using quoted market prices . interest income is recorded as earned . unrealized gains and losses , net of related income taxes , are reported as a component of accumulated other comprehensive income . upon sale , realized gains and losses on the sale of marketable securities are computed based on the specific identification of the underlying cost of the securities sold and the unrealized gains and losses previously reported in other comprehensive income are reclassified to current earnings. .