notes to consolidated financial statements 2014 ( continued ) the weighted average grant-date fair value of share awards granted in the years ended may 31 , 2007 and 2006 was $ 45 and $ 36 , respectively .the total fair value of share awards vested during the years ended may 31 , 2008 , 2007 and 2006 was $ 4.1 million , $ 1.7 million and $ 1.4 million , respectively .we recognized compensation expenses for restricted stock of $ 5.7 million , $ 2.7 million , and $ 1.6 million in the years ended may 31 , 2008 , 2007 and 2006 .as of may 31 , 2008 , there was $ 15.2 million of total unrecognized compensation cost related to unvested restricted stock awards that is expected to be recognized over a weighted average period of 2.9 years .employee stock purchase plan we have an employee stock purchase plan under which the sale of 2.4 million shares of our common stock has been authorized .employees may designate up to the lesser of $ 25 thousand or 20% ( 20 % ) of their annual compensation for the purchase of stock .for periods prior to october 1 , 2006 , the price for shares purchased under the plan was the lower of 85% ( 85 % ) of the market value on the first day or the last day of the quarterly purchase period .with the quarterly purchase period beginning on october 1 , 2006 , the price for shares purchased under the plan is 85% ( 85 % ) of the market value on the last day of the quarterly purchase period ( the 201cpurchase date 201d ) .at may 31 , 2008 , 0.7 million shares had been issued under this plan , with 1.7 million shares reserved for future issuance .the weighted average grant-date fair value of each designated share purchased under this plan was $ 6 , $ 8 and $ 8 in the years ended may 31 , 2008 , 2007 and 2006 , respectively .for the quarterly purchases after october 1 , 2006 , the fair value of each designated share purchased under the employee stock purchase plan is based on the 15% ( 15 % ) discount on the purchase date .for purchases prior to october 1 , 2006 , the fair value of each designated share purchased under the employee stock purchase plan was estimated on the date of grant using the black-scholes valuation model using the following weighted average assumptions: .
[['', '2007', '2006'], ['risk-free interest rates', '4.93% ( 4.93 % )', '3.72% ( 3.72 % )'], ['expected volatility', '37.02% ( 37.02 % )', '26.06% ( 26.06 % )'], ['dividend yields', '0.19% ( 0.19 % )', '0.34% ( 0.34 % )'], ['expected lives', '3 months', '3 months']]
the risk-free interest rate is based on the yield of a zero coupon united states treasury security with a maturity equal to the expected life of the option from the date of the grant .our assumption on expected volatility is based on our historical volatility .the dividend yield assumption is calculated using our average stock price over the preceding year and the annualized amount of our current quarterly dividend .since the purchase price for shares under the plan is based on the market value on the first day or last day of the quarterly purchase period , we use an expected life of three months to determine the fair value of each designated share. .

Question: what is the percentage change in the weighted average grant-date fair value of share awards from 2006 to 2007?
Answer: 25.0%