{"pre_text": ["prior to its adoption of sfas no .", "123 ( r ) , the company recorded compensation expense for restricted stock awards on a straight-line basis over their vesting period .", "if an employee forfeited the award prior to vesting , the company reversed out the previously expensed amounts in the period of forfeiture .", "as required upon adoption of sfas no .", "123 ( r ) , the company must base its accruals of compensation expense on the estimated number of awards for which the requisite service period is expected to be rendered .", "actual forfeitures are no longer recorded in the period of forfeiture .", "in 2005 , the company recorded a pre-tax credit of $ 2.8 million in cumulative effect of accounting change , that represents the amount by which compensation expense would have been reduced in periods prior to adoption of sfas no .", "123 ( r ) for restricted stock awards outstanding on july 1 , 2005 that are anticipated to be forfeited .", "a summary of non-vested restricted stock award and restricted stock unit activity is presented below : shares ( in thousands ) weighted- average date fair ."], "post_text": ["as of december 31 , 2007 , there was $ 15.3 million of total unrecognized compensation cost related to non-vested awards .", "this cost is expected to be recognized over a weighted-average period of 1.6 years .", "the total fair value of restricted shares and restricted stock units vested was $ 11.0 million , $ 7.5 million and $ 4.1 million for the years ended december 31 , 2007 , 2006 and 2005 , respectively .", "employee stock purchase plan the shareholders of the company previously approved the 2002 employee stock purchase plan ( 201c2002 purchase plan 201d ) , and reserved 5000000 shares of common stock for sale to employees at a price no less than 85% ( 85 % ) of the lower of the fair market value of the common stock at the beginning of the one-year offering period or the end of each of the six-month purchase periods .", "under sfas no .", "123 ( r ) , the 2002 purchase plan was considered compensatory .", "effective august 1 , 2005 , the company changed the terms of its purchase plan to reduce the discount to 5% ( 5 % ) and discontinued the look-back provision .", "as a result , the purchase plan was not compensatory beginning august 1 , 2005 .", "for the year ended december 31 , 2005 , the company recorded $ 0.4 million in compensation expense for its employee stock purchase plan for the period in which the 2002 plan was considered compensatory until the terms were changed august 1 , 2005 .", "at december 31 , 2007 , 757123 shares were available for purchase under the 2002 purchase plan .", "401 ( k ) plan the company has a 401 ( k ) salary deferral program for eligible employees who have met certain service requirements .", "the company matches certain employee contributions ; additional contributions to this plan are at the discretion of the company .", "total contribution expense under this plan was $ 5.7 million , $ 5.7 million and $ 5.2 million for the years ended december 31 , 2007 , 2006 and 2005 , respectively. ."], "table": [["", "shares ( in thousands )", "weighted- average grant date fair value"], ["non-vested at december 31 2006:", "2878", "$ 13.01"], ["issued", "830", "$ 22.85"], ["released ( vested )", "-514 ( 514 )", "$ 15.93"], ["canceled", "-1197 ( 1197 )", "$ 13.75"], ["non-vested at december 31 2007:", "1997", "$ 15.91"]], "table_ori": [["", "Shares (in thousands)", "Weighted- Average Grant Date Fair Value"], ["Non-vested at December 31, 2006:", "2,878", "$13.01"], ["Issued", "830", "$22.85"], ["Released (vested)", "(514)", "$15.93"], ["Canceled", "(1,197)", "$13.75"], ["Non-vested at December 31, 2007:", "1,997", "$15.91"]]}

Question: what was the percentage change in total contribution expense under the plan between 2006 and 2007?
Evidence:
text_21: total contribution expense under this plan was $ 5.7 million , $ 5.7 million and $ 5.2 million for the years ended december 31 , 2007 , 2006 and 2005 , respectively. .
Program: subtract(5.7, 5.7), divide(#0, 5.7)
Answer:
str_answer: 0%
exe_answer: 0