pre_text: the fair value for these options was estimated at the date of grant using a black-scholes option pricing model with the following weighted-average assumptions for 2006 , 2005 and 2004: .
post_text: the black-scholes option valuation model was developed for use in estimating the fair value of traded options which have no vesting restrictions and are fully transferable . in addition , option valuation models require the input of highly subjective assumptions , including the expected stock price volatility . because the company 2019s employee stock options have characteristics significantly different from those of traded options , and because changes in the subjective input assumptions can materially affect the fair value estimate , in management 2019s opinion , the existing models do not necessarily provide a reliable single measure of the fair value of its employee stock options . the total fair value of shares vested during 2006 , 2005 , and 2004 was $ 9413 , $ 8249 , and $ 6418 respectively . the aggregate intrinsic values of options outstanding and exercisable at december 30 , 2006 were $ 204.1 million and $ 100.2 million , respectively . the aggregate intrinsic value of options exercised during the year ended december 30 , 2006 was $ 42.8 million . aggregate intrinsic value represents the positive difference between the company 2019s closing stock price on the last trading day of the fiscal period , which was $ 55.66 on december 29 , 2006 , and the exercise price multiplied by the number of options outstanding . as of december 30 , 2006 , there was $ 64.2 million of total unrecognized compensation cost related to unvested share-based compensation awards granted to employees under the option plans . that cost is expected to be recognized over a period of five years . employee stock purchase plan the shareholders also adopted an employee stock purchase plan ( espp ) . up to 2000000 shares of common stock have been reserved for the espp . shares will be offered to employees at a price equal to the lesser of 85% ( 85 % ) of the fair market value of the stock on the date of purchase or 85% ( 85 % ) of the fair market value on the enrollment date . the espp is intended to qualify as an 201cemployee stock purchase plan 201d under section 423 of the internal revenue code . during 2006 , 2005 , and 2004 , 124693 , 112798 , and 117900 shares were purchased under the plan for a total purchase price of $ 3569 , $ 2824 , and $ 2691 , respectively . at december 30 , 2006 , approximately 1116811 shares were available for future issuance. .
table: 2006 2005 2004
table: Weighted average fair value of options granted $20.01 $9.48 $7.28
table: Expected volatility 0.3534 0.3224 0.3577
table: Distribution yield 1.00% 0.98% 1.30%
table: Expected life of options in years 6.3 6.3 6.3
table: Risk-free interest rate 5% 4% 4%
question: Analyse this data from a financial earnings document. considering the weighted average fair value of options , what was the decrease between shares that vested in 2006 and 2005?