insurance arrangement . as a result of the adoption of this new guidance , the company recorded a liability representing the actuarial present value of the future death benefits as of the employees 2019 expected retirement date of $ 45 million with the offset reflected as a cumulative-effect adjustment to january 1 , 2008 retained earnings and accumulated other comprehensive income ( loss ) in the amounts of $ 4 million and $ 41 million , respectively , in the company 2019s consolidated statement of stockholders 2019 equity . it is currently expected that minimal , if any , further cash payments will be required to fund these policies . the net periodic cost for these split-dollar life insurance arrangements was $ 6 million in both the years ended december 31 , 2009 and 2008 . the company has recorded a liability representing the actuarial present value of the future death benefits as of the employees 2019 expected retirement date of $ 48 million and $ 47 million as of december 31 , 2009 and december 31 , 2008 , respectively . defined contribution plan the company and certain subsidiaries have various defined contribution plans , in which all eligible employees participate . in the u.s. , the 401 ( k ) plan is a contributory plan . matching contributions are based upon the amount of the employees 2019 contributions . effective january 1 , 2005 , newly hired employees have a higher maximum matching contribution at 4% ( 4 % ) on the first 5% ( 5 % ) of employee contributions , compared to 3% ( 3 % ) on the first 6% ( 6 % ) of employee contributions for employees hired prior to january 2005 . effective january 1 , 2009 , the company temporarily suspended all matching contributions to the motorola 401 ( k ) plan . the company 2019s expenses , primarily relating to the employer match , for all defined contribution plans , for the years ended december 31 , 2009 , 2008 and 2007 were $ 8 million , $ 95 million and $ 116 million , respectively . 8 . share-based compensation plans and other incentive plans stock options , stock appreciation rights and employee stock purchase plan the company grants options to acquire shares of common stock to certain employees , and existing option holders in connection with the merging of option plans following an acquisition . each option granted and stock appreciation right has an exercise price of no less than 100% ( 100 % ) of the fair market value of the common stock on the date of the grant . the awards have a contractual life of five to ten years and vest over two to four years . stock options and stock appreciation rights assumed or replaced with comparable stock options or stock appreciation rights in conjunction with a change in control only become exercisable if the holder is also involuntarily terminated ( for a reason other than cause ) or quits for good reason within 24 months of a change in control . the employee stock purchase plan allows eligible participants to purchase shares of the company 2019s common stock through payroll deductions of up to 10% ( 10 % ) of eligible compensation on an after-tax basis . plan participants cannot purchase more than $ 25000 of stock in any calendar year . the price an employee pays per share is 85% ( 85 % ) of the lower of the fair market value of the company 2019s stock on the close of the first trading day or last trading day of the purchase period . the plan has two purchase periods , the first one from october 1 through march 31 and the second one from april 1 through september 30 . for the years ended december 31 , 2009 , 2008 and 2007 , employees purchased 29.4 million , 18.9 million and 10.2 million shares , respectively , at purchase prices of $ 3.60 and $ 3.68 , $ 7.91 and $ 6.07 , and $ 14.93 and $ 15.02 , respectively . the company calculates the value of each employee stock option , estimated on the date of grant , using the black-scholes option pricing model . the weighted-average estimated fair value of employee stock options granted during 2009 , 2008 and 2007 was $ 2.78 , $ 3.47 and $ 5.95 , respectively , using the following weighted-average assumptions : 2009 2008 2007 .

Table:
 | 2009 | 2008 | 2007
expected volatility | 57.1% ( 57.1 % ) | 56.4% ( 56.4 % ) | 28.3% ( 28.3 % )
risk-free interest rate | 1.9% ( 1.9 % ) | 2.4% ( 2.4 % ) | 4.5% ( 4.5 % )
dividend yield | 0.0% ( 0.0 % ) | 2.7% ( 2.7 % ) | 1.1% ( 1.1 % )
expected life ( years ) | 3.9 | 5.5 | 6.5
.

Question: what is the percent change in number of shares purchased by employees between 2008 and 2009?
Answer: 56%
Calculation: subtract(29.4, 18.9), divide(#0, 18.9)